The results of Berzelius were greatly extended by Hermann Kopp, who recognized that carbon, boron and silicon were exceptions to the law.
Scheele had done, and because he was employing a glass vessel he got "fluor acid air" (silicon fluoride).
By heating crystallized silicon with boron in the electric furnace H.
The octochloride, Si 3 C1 8r is formed to the extent of about 2 to 1% in the action of chlorine on silicon (L.
Silicon chloride, SiC1 41 was prepared by J.
Wailer (Ann., 1857, 104, p. 94), is formed by heating crystallized silicon in hydrochloric acid gas at a temperature below red heat, or by the action of hydrochloric acid gas on copper silicide, the products being condensed by liquid air and afterwards fractionated (0.
For silicon carbide see carborundum.
David Dean, without a remote control, had difficulty with the TV and these two old fogies were out surfing the net like a couple of Silicon Valley youngsters.
Like silicon and carbon, very varying values had been given for its specific heat, until H.
Normal values of K were given by nitrogen peroxide, N204, sulphur chloride, S 2 C1 21 silicon tetrachloride, SiC1 4, phosphorus chloride, PC1 3, phosphoryl chloride, POC1 31 nickel carbonyl, Ni(CO) 4, carbon disulphide, benzene, pyridine, ether, methyl propyl ketone; association characterized many hydroxylic compounds: for ethyl alcohol the factor of association was 2.74-2.43, for n-propyl alcohol 2.86-2.72, acetic acid 3.62 -2.77, acetone 1 .
The addition of silicon in small quantities considerably diminished permeability and increased coercive force; but when the proportion amounted to 2.5% the maximum permeability (µ =5100 for H =2) was greater than that of the nearly pure iron used for comparison, while the coercive force was only 0.9.
It burns when brought into contact with chlorine, forming silicon chloride and hydrochloric acid.
A second hydride of silicon, of composition Si 2 H 6, was prepared by H.
phys., 1880, (5), 20, P. 5 Only one oxide of silicon, namely the dioxide or silica, is known.
Silicon fluoroform, SiHF 3, was obtained by 0.
Ruff and Curt Albert (Ber., 1905, 38, p. 53) by decomposing titanium fluoride with silicon chloroform in sealed vessels at 100 -120° C. It is a colourless gas which may be condensed to a liquid boiling at -80 2° C. On solidification it melts at about -110° C. The gas is very unstable, decomposing slowly, even at ordinary temperatures, into hydrogen,, silicon fluoride and silicon: 4SiHF 3 =2H 2 +3SiF 4 +Si.
Silicofluoric acid, H2SiF6, is obtained as shown above, and also by the action of sulphuric acid on barium silicofluoride, or by absorbing silicon fluoride in aqueous hydrofluoric acid.
The anhydrous acid is not known, since on evaporating the aqueous solution it gradually decomposes into silicon fluoride and hydrofluoric acid.
Berzelius (Jahresb., 182 5, 4, p. 91) by the action of chlorine on silicon, and is also obtained when an intimate mixture of silica and carbon is heated in a stream of chlorine and the products of reaction fractionated.
When heated with the alkali and alkaline earth metals it yields silicon and the corresponding metallic chlorides.
6NH 31 and it also serves as the starting point for the preparation of numerous organic derivatives of silicon.
The hexachloride, Si 2 C1 61 is formed when silicon chloride vapour is passed over strongly heated silicon; by the action of chlorine on the corresponding iodocompound, or by heating the iodo-compound with mercuric chloride (C. Friedel, Comptes rendus, 18 7 1, 73, P. 497).
Silicon chloroform, SiHC1 3, first prepared by H.
5 More than fifty different specimens were tested, most of which contained a known proportion of manganese, nickel, tungsten, aluminium, chromium, copper or silicon; in some samples two of the substances named were present.
Silicon fluoride, SiF4, is formed when silicon is brought into contact with fluorine (Moissan); or by decomposing a mixture of acid potassium fluoride and silica, or of calcium fluoride and silica with concentrated sulphuric acid.
Carbon was joined with silicon, zirconium and titanium, while boron, being trivalent, was relegated to another group. A general classification of elements, however, was not realized by Frankland, nor even by Odling, who had also investigated the question from the valency standpoint.
A masterly device, initiated by him, was to collect gases over mercury instead of water; this enabled him to obtain gases previously only known in solution, such as ammonia, hydrochloric acid, silicon fluoride and sulphur dioxide.
The success which attended his experiments in the case of silicon led him to apply it to the isolation of other elements.
The term allotropy has also been applied to inorganic compounds, identical in composition, but assuming different crystallographic forms. Mercuric oxide, sulphide and iodide; arsenic trioxide; titanium dioxide and silicon dioxide may be cited as examples.
Weber, who showed that with rise of temperature the specific (and atomic) heat increases, finally attaining a fairly constant value; diamond, graphite and the various amorphous forms of carbon having the value about 5.6 at moo°, and silicon 5.68 at 232°; while he concluded that boron attained a constant value of 5.5.
Mehner patented heating the oxides of silicon, boron or magnesium with coal or coke in an electric furnace, and then passing in nitrogen, which forms, with the metal liberated by the action of the carbon, a readily decomposable nitride.
At the same time, however, it forms a number of compounds in which it is most decidedly tetravalent; and thus it shows relations to carbon, silicon, germanium and tin.
Trans., 1885, 176, 455) employed his yoke method to test the magnetic properties of thirty-five samples of iron and steel, among which were steels containing substantial proportions of manganese, silicon, chromium and tungsten.
GERMANIUM (symbol Ge, atomic weight 72.5); one of the metallic elements included in the same natural family as carbon, silicon, tin and lead.
For additional information regarding the composition and qualities of permanent magnet steels reference may be made 6 The marked effect of silicon in increasing the permeability of cast iron has also been noticed by F.
1839), for many years a professor at the Massachusetts Institute of Technology, Boston, he obtained various organometallic compounds of silicon.
A few years later further work, with Albert Ladenburg, on the same element yielded silicochloroform and:led to a demonstration of the close analogy existing between the behaviour in combination of silicon and carbon.
The older methods used for the preparation of the amorphous form, namely the decomposition of silicon halides or silicofluorides by the alkali metals, or of silica by magnesium, do not give good results, since' the silicon obtained is always contaminated with various impurities, but a pure variety may be prepared according to E.
A somewhat impure silicon (containing 90-98% of the element) is made by the Carborundum Company of Niagara Falls (United States Patents 745 122 and 842273, 1908) by heating coke and sand in an electric furnace.
The product is a crystalline solid of specific gravity 2.34, and melts at about 1430° C. See also German Patent 108817 for the production of crystallized silicon from silica and carborundum.
The specific heat varies with the temperature, from 0.136 at -39° C. to 0.2029 at 232° C. Silicon distils readily at the temperature of the electric furnace.
It decomposes ammonia at a red heat, liberating hydrogen and yielding a compound containing silicon and nitrogen.
Silicon hydride, SiH4, is obtained in an impure condition, as a spontaneously inflammable gas, by decomposing magnesium silicide with hydrochloric acid, or by the direct union of silicon and hydrogen in the electric arc. In the pure state it may be prepared by decomposing ethyl silicoformate in the presence of sodium (C. Friedel and A.
Silicon tetraiodide, Si14, is formed by passing iodine vapour mixed with carbon dioxide over strongly-heated silicon (C. Friedel, Comptes rendus, 1868, 67, p. 98); the iodo-compound condenses in the colder portion of the apparatus and is purified by shaking with carbon bisulphide and with mercury.
Silicon iodoform, SiHI 3, is formed by the action of hydriodic acid on silicon, the product, which contains silicon tetraiodide, being separated by fractionation.
It is also obtained by the action of hydriodic acid on silicon nitrogen hydride suspended in carbon bisulphide, or by the action of a benzene solution of hydriodic acid on trianilino-silicon hydride (0.
Numerous chloro-iodides and bromoiodides of silicon have been described.
Silicon nitrogen hydride, SiNH, is a white powder formed with silicon amide when ammonia gas (diluted with hydrogen) is brought into contact with the vapour of silicon chloroform at -10° C. Trianilino silicon hydride, SiH (NHC 6 H 5) 3, is obtained by the action of aniline on a benzene solution of silicon chloroform.
Silicon sulphide, SiS 2, is formed by the direct union of silicon with sulphur; by the action of sulphuretted hydrogen on crystallized silicon at red heat (P. Sabatier, Comptes rendus, 1880, 90, p. 819); or by passing the vapour of carbon bisulphide over a heated mixture of silica and carbon.
Alloys of magnesium and silicon are prepared by heating fragments of magnesium with magnesium filings and potassium silico-fluoride.
From the alloy containing 25% of silicon, the excess of magnesium is removed by a mixture of ethyl iodide and ether and a residue consisting of slate-blue octahedral crystals of magnesium silicide is left.
It decomposes water at ordinary temperature with evolution of hydrogen but without production of silicon hydride, whilst cold hydrochloric acid attacks it vigorously with evolution of hydrogen and spontaneously inflammable silicon hydride.
Organic Derivatives of Silicon.
The organic derivatives of silicon resemble the corresponding carbon compounds except in so far that the silicon atom is not capable of combining with itself to form a complex chain in the same manner as the carbon atom, the limit at present being a chain of three silicon atoms. Many of the earlier-known silicon alkyl compounds were isolated by Friedel and Crafts and by Ladenburg, the method adopted consisting in the interaction of the zinc alkyl compounds with silicon halides or esters of silicic acids.
Taurke (Ber., 1905, 38, p. 1663) by condensing silicon halides with alkyl chlorides in the presence of sodium: SiC14-1-4R Cl+8Na= SiR 4 +8NaCI; SiHC1 3 +3R.
Soc., 1904, 20, p. 15) has used silicon halides with the Grignard reagent: C2H,MgBr(+SiC14)-C2HiSiC13(-1-MgBrPh)--> Ph C 2 H 1.
Silicon Tetramethyl, Si(CH3)4 (tetramethyl silicane), and silicon tetraethyl, Si(C2H5)4, are both liquids.
The latter reacts with chlorine to give silicon nonyl-chloride Si(C2H5)3 C2H4C1, which condenses with potassium acetate to give the acetic ester of silicon nonyl alcohol from which the alcohol (a camphor-smelling liquid) may be obtained by hydrolysis.
Silicon tetraphenyl, Si(C6H5)4, a solid melting at 231° C., is obtained by the action of chlorobenzene on silicon tetrachloride in the presence of sodium.
OH) 2, obtained by decomposing silicon hexachloride with icecold water, is an unstable solid which is readily decomposed by the inorganic bases, with evolution of hydrogen and production of a silicate.
OH, formed by the action of moist air on silicon octochloride at o° C., is very unstable, and hot water decomposes it with evolution of hydrogen and formation of silicic acid (L.
Silicobenzoic acid, C 6 H 5 S10.0H, results from the action of dilute aqueous ammonia on phenyl silicon chloride (obtained from mercury diphenyl and silicon tetrachloride).
It is a colourless solid which melts at 92° C. For silicon derivatives of the amines see Michaelis, Ber., 1896, 29, p. 710; on asymmetric silicon and the resolution of dl-benzyl-ethyl-propyl-silicol see F.
The atomic weight of silicon has been determined usually by analysis of the halide compounds or by conversion of the halides into silica.
Silicon, so far as we know, behaves to metals pretty much like carbon, but our knowledge of facts is limited.
What is known as cast iron is essentially an alloy of iron proper with 2 to 6% of carbon and more or less of silicon.
Alloys of copper and silicon were prepared by Deville in 1863.
The alloy with 12% of silicon is white, hard and brittle.
Chemically pure sand is silicon dioxide (SiO 2) or quartz, a clear transparent glass-like mineral, but as ordinarily met with, it is more or less impure and generally coloured reddish or yellowish by oxide of iron.
The following table shows the amounts of the chief constituents removed by certain crops in lb per acre: - Plants also remove from the soil silicon, sodium, chlorine, and other elements which are, nevertheless, found to be unessential for the growth and may therefore be neglected here.
His contributions to inorganic chemistry were numerous, including investigations on the compounds of antimony, aluminium, silicon, &c., on the separation of nickel and cobalt, and on the analysis of mineral waters, but they are outweighed in importance by his work on organic substances.
Although at the present time a marvellous improvement has taken place all round in the quality of the carbide produced, the acetylene nearly always contains minute traces of hydrogen, ammonia, sulphuretted hydrogen, phosphuretted hydrogen, silicon hydride, nitrogen and oxygen, and sometimes minute traces of carbon monoxide and dioxide.
The presence of free hydrogen is nearly always accompanied by silicon hydride formed by the combination of the nascent hydrogen with the silicon in the carbide.
Its most important property is that it rapidly attacks glass, reacting with the silica of the glass to form gaseous silicon fluoride, and consequently it is used for etching.
Fluorides can be readily detected by their power of etching glass when warmed with sulphuric acid; or by warming them in a glass tube with concentrated sulphuric acid and holding a moistened glass rod in the mouth of the tube, the water apparently gelatinizes owing to the decomposition of the silicon fluoride formed.
Sodium is largely employed in the manufacture of cyanides and in reduction processes leading to the isolation of such elements as magnesium, silicon, boron, aluminium (formerly), &c.; it also finds application in organic chemistry.
It combines directly with silicon, at the temperature of the electric furnace, yielding carborundum, SiC; and H.
It is a most powerful oxidizing agent, phosphorus being readily oxidized to phosphoric acid, arsenic to arsenic acid, silicon at 250° C. to silica, and hydrochloric acid to chlorine and water.
Conspicuous examples are afforded by oxygen, carbon, boron, silicon, phosphorus, mercuric oxide and iodide.
If, according to the present method of winning the metal, a bath containing silica as well as alumina is submitted to electrolysis, both oxides are dissociated, and as silicon is a very undesirable impurity, an alumina contaminated with silica is not suited for reduction.
Two grave disadvantages were soon obvious - the limited supply of ore, and, what was even more serious, the large proportion of silicon in the reduced metal.
Commercial electrolytic aluminium of the best quality contains as the average of a large number of tests, 0.48% of silicon and 0.46% of iron, the residue being essentially aluminium itself.
Buff carried out an inquiry on the compounds of silicon in which they prepared the previously unknown gas, silicon hydride or silicuretted hydrogen.
Just as variations in the carbon-content shift the temperature of the freezing-range and of the various critical points, so do variations in the content of other elements, notably silicon, phosphorus, manganese, chromium, nickel and tungsten.
Slow cooling, slow solidification, the presence of an abundance of carbon, and the presence of silicon, all favour the formation of graphite; rapid cooling, the presence of sulphur, and in most cases that of manganese, favour the formation of cementite.
On its way from the blast furnace to the converter or open hearth furnace the pig iron is often passed through a great reservoir called a " mixer," which acts also as an equalizer, to lessen the variation in composition of the cast iron, and as a purifier, removing part of the sulphur and silicon.
In the former case there is no later chance to remove sulphur, a minute quantity of which does great harm by leading to the formation of cementite instead of graphite and ferrite, and thus making the cast-iron castings too hard to be cut to exact shape with steel tools; in the latter case the converting or purifying processes, which are essentially oxidizing ones, though they remove the other impurities, carbon, silicon, phosphorus and manganese, are not well adapted to desulphurizing, which needs rather deoxidizing conditions, so as to cause the formation of calcium sulphide, than oxidizing ones.
The chief difficulty in the way of modifying the blastfurnace process itself so as to make it accomplish what the direct processes aim at, by giving its product less carbon and silicon than pig iron as now made contains, is the removal of the sulphur.
Moreover, the quality of the resultant steel depends upon the temperature of the process, and this in turn depends upon the proportion of silicon, the combustion of which is the chief source of the heat developed.
An excess of silicon or sulphur in the cast iron from one blastfurnace is diluted by thus mixing this iron with that from the other furnaces.
Should several furnaces simultaneously make iron too rich in silicon, this may be diluted by pouring into the mixer some low-silicon iron melted for this purpose in a cupola furnace.
Further, an important part of the silicon may be removed in the mixer by keeping it very hot and covering the metal with a rather basic slag.
This is very useful if the iron is intended for either the basic Bessemer or the basic open-hearth process, for both of which silicon is harmful.
As the essential difference between cast iron on one hand and wrought iron and steel on the other is that the former contains necessarily much more carbon, usually more silicon, and often more phosphorus that are suitable or indeed permissible in the latter two, the chief work of all these conversion processes is to remove the excess of these several foreign elements by oxidizing them to carbonic oxide CO, silica S102, and phosphoric acid P 2 0 5, respectively.
Beside this their chief and easy work of oxidizing carbon, silicon and phosphorus, the conversion processes have the harder task of removing sulphur, chiefly by converting it into calcium sulphide, CaS, or manganous sulphide, MnS, which rise to the top of the molten metal and there enter the overlying slag, from which the sulphur may escape by oxidizing to the gaseous compound, sulphurous acid, S02.
low-carbon slag-bearing iron, by oxidizing its carbon, silicon and.
As the iron oxide is stirred into the molten metal laboriously by the workman or "puddler " with his hook or "rabble," it oxidizes the silicon to silica and the phosphorus to phosphoric acid, and unites with both these products, forming with them a basic iron silicate rich in phosphorus, called " puddling " or " tap cinder."
But this basicity implies that for each part of the silica or silicic acid which inevitably results from the oxidation of the silicon of the pig iron, the cinder shall contain some three parts of iron oxide, itself a valuable and expensive substance.
Hence, in order to save iron oxide the pig iron used should be nearly free from silicon.
But the strong deoxidizing conditions needed in the blast-furnace to remove sulphur tend strongly to deoxidize silica and thus to make the pig iron rich in silicon.
The " refinery process " of fitting pig iron for the puddling process by removing the silicon without the carbon, is sometimes used because of this difficulty in making a pig iron initially low in both sulphur and silicon.
In this process molten pig iron with much silicon but little sulphur has its silicon oxidized to silica and thus slagged off, by means of a blast of air playing on the iron through a blanket of burning coke which covers it.
The coke thus at once supplies by its combustion the heat needed for melting the iron and keeping it hot, and by itself dissolving in the molten metal returns carbon to it as fast as this element is burnt out by the blast, so that the " refined " cast iron which results, though still rich in carbon and therefore easy to melt in the puddling process, has relatively little silicon.
Under normal conditions the silicon oxidizes first.
- Bessemer had no very wide knowledge of metallurgy, and after overcoming many stupendous ' The length of the blow varies very greatly, in general increasing with the proportion of silicon and with the size of charge.
Thus the small Swedish charges with but little silicon may be blown in 5 minutes, but for a 20-ton charge the time is more likely to reach or exceed 10 minutes, and sometimes reaches 20 minutes or even more.
Thus it comes about that the temperature is regulated primarily by adjusting the quantity of silicon in the pig iron treated, of this element usually sufficing.
The basic or dephosphorizing variety of the Bessemer process, called in Germany the " Thomas " process, differs from the acid process in four chief points: (i) that its slag is made very basic and hence dephosphorizing by adding much lime to it; (2) that the lining is basic, because an acid lining would quickly be destroyed by such a basic slag; (3) that the process is arrested not at the " drop of the flame " (§85) but at a predetermined length of time after it; and (4) that phosphorus instead of silicon is the chief source of heat.
The slag, in order that it may have such an excess of base that this will retain the phosphoric acid as fast as it is formed by the oxidation of the phosphorus of the pig iron, and prevent it from being re-deoxidized and re-absorbed by the iron, should, according to von Ehrenwerth's rule which is generally followed, contain enough lime to form approximately a tetra-calcic silicate, 4CaO,S10 2 with the silica which results from the oxidation of the silicon of the pig iron and tri-calcic phosphate, 3CaO,P205, with the phosphoric acid which forms. The danger of this " rephosphorization " is greatest at the end of the blow, when the recarburizing additions are made.
- Silicon cannot here be used as the chief source of heat as it is in the acid Bessemer process, because most of the heat which its oxidation generates is consumed in heating the great quantities of lime needed for neutralizing the resultant silica.
Further objections to the presence of silicon are that the resultant silica (1) corrodes the lining of the converter, (2) makes the slag froth so that it both throws much of the charge out and blocks up the nose of the converter, and (3) leads to rephosphorization.
These effects are so serious that until very lately it was thought that the silicon could not safely be much in excess of i %.
But Massenez and Richards, following the plan outlined by Pourcel in 1879, have found that even 3% of silicon is permissible if, by adding iron ore, the resultant silica is made into a fluid slag, and if this is removed in the early cool part of the process, when it attacks the lining of the converter but slightly.
Indeed, no limit has yet been found to the temperature which can be reached, if matters are so arranged that not only the carbon and silicon of the pig iron, but also a considerable part of the metallic iron which is the iron itself, are oxidized by the blast; or if, as in the Walrand-Legenisel modification, after the combustion of the initial carbon and silicon of the pig iron has already raised the charge to a very high temperature, a still further rise of temperature is brought about by adding more silicon in the form of ferro-silicon, and oxidizing it by further blowing.
But no part of the Bessemer converter is of a shape easily affected by the heat, no part of it is exposed to the heat on more than one side, and the converter itself is necessarily cooler than the metal within it, because the heat is generated within the metal itself by the combustion of its silicon and other calorific elements.
version of cast iron into steel, of course, consists in lessening its content of the several foreign elements, carbon, silicon, phosphorus, &c. The open-hearth process does this by two distinct steps: (I) by oxidizing and removing these elements by means of the flame of the furnace, usually aided by the oxygen of light charges of iron ore, and (2) by diluting them with scrap steel or its equivalent.
He then pours or taps the molten charge from the furnace into a large clay-lined casting ladle, giving it the final additions of manganese, usually with carbon and often with silicon, needed to give it exactly the desired composition.
In some British and Swedish " pig and ore " practice (§ 98), on the other hand, little or no scrap is used, and here the removal of the large quantity of carbon, silicon and phosphorus prolongs the process to 17 hours.
The pig and ore process is held back, first by the large quantity of carbon, and usually of silicon and phosphorus, to be removed, and second by the necessary slowness of their removal.
At this time the slag is temporarily rich in iron oxide and silica, resulting from the oxidation of the iron and of its silicon as the charge slowly melts and trickles down.
In the former the silicon and part of the carbon are moved rapidly, in the latter the rest of the carbon and the phosphorus are removed slowly, and the metal is brought accurately to the proper temperature and composition.
For the acid Bessemer process the sulphur-content must be small and the silicon-content should be constant; for the basic openhearth process the content of both silicon and sulphur should be small, a thing difficult to bring about, because in the blast furnace most of the conditions which make for small sulphur-content make also for large silicon-content.
In the acid Bessemer process the reason why the sulphur-content must be small is that the process removes no sulphur; and the reason why the silicon-content should be constant is that, because silicon is here the chief source of heat, variations in its content cause corresponding variations in the temperature, a most harmful thing because it is essential to the good quality of the steel that it shall be finished and cast at the proper temperature.
In the basic open-hearth process, on the other hand, silicon is harmful because the silica which results from its oxidation not only corrodes the lining of the furnace but interferes with the removal of the phosphorus, an essential part of the process.
But if the silicon of the pig iron is removed by a preliminary treatment in the Bessemer converter, then its presence in the pig iron is harmless as regards the open-hearth process.
This enables it to take up enough silicon from the walls of the crucible to prevent the evolution of gas during solidification, and the consequent formation of blowholes or internal gas bubbles.
In the Bell-Krupp or "pig-washing" process, invented independently by the famous British iron-master, Sir Lowthian Bell, and Krupp of Essen, advantage is taken of the fact that, at a relatively low temperature, probably a little above 1200° C., the phosphorus and silicon of molten cast iron are quickly oxidized and removed by contact with molten iron oxide, though carbon is thus oxidized but slowly.
By rapidly stirring molten iron oxide into molten pig iron in a furnace shaped like a saucer, slightly inclined and turning around its axis, at a temperature but little above the melting-point of the metal itself, the phosphorus and silicon are removed rapidly, without removing much of the carbon, and by this means an extremely pure cast iron is made.
Electric furnaces are at an advantage over others as regards the removal of sulphur and of iron oxide from the molten steel, because their atmosphere is free from the sulphur always present in the flame of coal-fired furnaces, and almost free from oxygen, because this element is quickly absorbed by the carbon and silicon of the steel, and in the case of arc furnaces by the carbon of the electrodes themselves, and is replaced only very slowly by leakage, whereas through the Bessemer converter and the open-hearth furnace a torrent of air is always rushing.
But cast iron for the basic open-hearth process can be made from almost any ore, because its requirements, comparative freedom from silicon and sulphur, depend on the management of the blast-furnace rather than on the composition of the ore, whereas the phosphorus-content of the cast iron depends solely on that of the ore, because nearly all the phosphorus of the ore necessarily passes into the cast iron.
Of these several qualities which cast iron may have, fluidity is given by keeping the sulphur-content low and phosphoruscontent high; and this latter element must be kept low if shock is to be resisted; but strength, hardness, endurance of shock, density and expansion in solidifying are controlled essentially by the distribution of the carbon between the states of graphite and cementite, and this in turn is controlled chiefly by the proportion of silicon, manganese and sulphur present, and in many cases by the rate of cooling.
If this carbon is all present as graphite, so that in cooling the graphite-austenite diagram has been followed strictly (§ 26), the constitution is extremely simple; clearly the mass consists first of a metallic matrix, the carbonless iron itself with whatever silicon, manganese, phosphorus and sulphur happen to be present, in short an impure ferrite, encased in which as a wholly distinct foreign body is the graphite.
Thus thick machinery castings usually contain between 1.50 and 2.25% of silicon, whereas thin castings and ornamental ones which must reproduce the finest details of the mould accurately may have as much as 3 or even 3.4 0% of it.
Castings which, like hydraulic press cylinders and steam radiators, must be dense and hence must have but little graphite lest their contents leak through their walls, should not have more than 1.75% of silicon and may have even as little as 1% if impenetrability is so important that softness and consequent ease of machining must be sacrificed to it.
Blowholes may be lessened or even wholly prevented by adding to the molten metal shortly before it solidifies either silicon or aluminium, or both; even as little as 0.002% of aluminium is usually sufficient.
This is done chiefly by casting the steel at a relatively low temperature, and by limiting the quantity of manganese and silicon which it contains.
silicon equals 1.66, there will be no blowholes; if this sum is less, blowholes will occur, and will be injuriously near the surface unless this sum is reduced to o 28.
The cast-iron contained nearly 3% each of silicon and graphite, and 1% each of phosphorus and manganese.
4% of silicon, and 0.5% of manganese.
The metal as obtained by industrial methods rarely contains more than about 99-99.5% of nickel, the chief impurities being copper, iron, cobalt, silicon and carbon.
It combines with fluorine with incandescence at ordinary temperatures, and with chlorine at 250-300°; carbon, silicon, and boron, when heated with it in the electric furnace, give crystals harder than the ruby.
The waters are tasteless and inodorous, and contain calcium and magnesium bicarbonates, combinations of hydrogen and silicon, and of iodides, bromides and lithium.
By the direct union of copper and silicon, cuprosilicon, consisting mainly of Cu 4 Si, is obtained (Lebeau, C.R., 1906; Vigouroux, ibid.).
QUARTZ, a widely distributed mineral species, consisting of silicon dioxide, or silica (S102).
It combines with the halide derivatives of boron and silicon to form, e.g.
It has no action on glass in the cold, but when heated it gives phosphorus and silicon tetrafluoride.
Heated in a glass tube it gives silicon fluoride, phosphorus and sulphur, PSF 3 = PF3-f-S; 4PF 3 +3S10 2 = 3SiF 4 +P 4 +30 2.
Dyson has measured some eight hundred lines in the lower chromosphere and identified them with emission spectra of the following elements: hydrogen, helium, carbon with the cyanogen band, sodium, magnesium, aluminium, silicon, calcium, scandium, titanium, vanadium, chromium, manganese, iron, zinc, strontium, yttrium, zirconium, barium, lanthanum, cerium, neodymium, ytterbium, lead, europium, besides a few doubtful identifications; it is a curious fact that the agreement is with the spark spectra of these elements, where the photosphere shows exclusively or more definitely the arc lines, which are generally attributed to a lower temperature.
By the addition of a small quantity of silicon the tensile strength of copper is much increased; a sample of such silicon bronze, used for telegraph wires, on analysis was found to consist of 99.94% of copper, 0.03% of tin, and traces of iron and silicon.
Siloxicon, a compound of carbon, silicon and oxygen, formed from carbon and silica in the electric furnace, was patented by E.
An amorphous, soft silicon carbide, also formed in the electric furnace, was patented by B.
This is certainly the case with experimental micromachined diamond accelerometers analogous to those made in silicon.
amorphous silicon solar panel.
anisotropic etching of silicon enables the accurate fabrication of V-shaped grooves to locate optic fibers.
Semiconductor detectors are usually used: the most common are silicon, lead sulfide, indium antimonide or indium gallium arsenide.
As the silicon crystal grows oxygen is incorporated as an interstitial atom in the silicon matrix at a concentration of typically 10-40 ppm.
Silicon being a larger atom than carbon can form only a single covalent bond with an oxygen atom.
Using a system by Kawneer, they were fixed with a silicon gasket, then clip-in metal beading, then another gasket.
The process starts with a laser beam or electron beam writing a pattern on fused silica or silicon.
boron implanted silicon using defect engineering.
Bronze The usual alloy for fasteners is silicon bronze The usual alloy for fasteners is silicon bronze.
The single crystal silicon proof mass is free-standing and held by two silicon cantilevers.
Composite coatings of electroless nickel containing silicon carbide exhibits superior abrasive wear resistance to hard chromium plate in some applications.
Due to its high melting point, silicon carbide can only be processed in powder form.
The latter is determined by the lens aperture, CCD integration time, and the sensitivity of the silicon CCD detector.
silicon Glen now dominates a significant part of the European market for silicon chips.
The use of silicon allows precise micromachining of components with well defined thermal conductance.
crystalline silicon for photovoltaic applications.
Or there are those such as the extropians who see cyberspace as the natural home for human identities that have been uploaded onto silicon.
depletion layer of cations is produced in the glass adjacent to the silicon.
The construction of components, on the micron scale, is by silicon micromachining, electro deposition and thin film metal and dielectric deposition.
A lithium drifted silicon X-ray detector with high energy resolution enables these characteristic X-rays to be identified as coming from specific elements.
Pairs of neighboring atoms on the surface bind to each other to make silicon dimers.
A calibrated p-type silicon diode detector was used to measure the dose received by the patient in the center of the field.
This is also an example of the acidic silicon dioxide reacting with a base.
dopant atoms into the silicon to make these layers; ion implantation.
dopeis is a property of the crystal structure and can be controlled by doping the silicon with various impurities.
dot-com bubble in San Francisco was only the tip of the iceberg of a larger boom centered in Silicon Valley.
electron beam writing a pattern on fused silica or silicon.
HP have used memory bits made of rotaxanes, rather than silicon - the first significant demonstration of ' molecular electronics ' .
etched into the surface of the silicon.
Liquid anisotropic etching of silicon enables the accurate fabrication of V-shaped grooves to locate optic fibers.
The readout gaps are milled obliquely into silicon beams used focused ion beam etching.
eutectic composition, ie approximately 12% silicon.
They have a 5 " silicon wafer fabrication facility dedicated to CCD manufacture.
He believes the CSI, along with the silicon feedstock shortage and current high costs, will further accelerate the existing trend toward thin-film.
To achieve the speed gain, researchers at the University of Southampton added fluorine to the silicon devices.
However, the design capability is largely reliant on limited Far Eastern silicon foundry capacity.
foundrytechnique has also been embraced by wafer foundries and fabrication houses to produce duplicates from silicon masters, significantly saving on production costs.
fused silica or silicon.
A half dozen fuzz algorithms, from smooth germanium transistor fuzz to harsh silicon clipping fuzz boxes.
SiGe chips are similar to standard silicon chips, but they also contain germanium for better performance and lower power consumption.
An EU IST project is currently working on diffusion modeling in silicon germanium alloys.
grip silicon rubber compound.
The initial research concentrated on silicon gyroscopes, but the scope has diversified considerably from there.
Unexpectedly, the radiation hardness has been found to be worse than silicon under charged hadron irradiation.
dynamic holography using ferroelectric liquid crystal on silicon spatial light modulators M. P. B. Trinder, JE.
hydrogenated amorphous silicon (a-Si:H) than others?
interlocking silicon crystals grow together.
Figure 4: Low loss spectra from the unirradiated SiO 2, heavily irradiated SiO 2, heavily irradiated silicon particle and nanoporous silicon.
Darkened hallways instruments silicon valley's golden age seem hackneyed even ketchup sandwhiches during.
Silicon tetrachloride is a colorless liquid at room temperature which fumes in moist air.
litreduction of a single 6-inch silicon wafer results in 14 kilos of solid waste and 11,000 liters of wastewater.
The Company is pleased to report strong levels of interest for its advanced X-ray metrology tools to the silicon semiconductor.
BYERS: A biological equivalent of a silicon microchip.
These will transform our lives to a far greater extent than silicon microelectronics did in the 20th Century.
Grade 21 Titanium alloy including 15% molybdenum, 3% aluminum, 2.7% niobium, 0.25% silicon.
For example, we have produced silicon nitride containing small amounts of lanthanide ions.
Figure 4 shows an optical image of a silicon nitride block which has been damaged on the right side.
Indeed, his silicon city of the future will be so familiar to readers of science fiction as to appear almost old-fashioned.
outflow pipe, which we then sealed with silicon sealant.
Several research groups world-wide aim to advance the methodology of direct silicon implementations in an attempt to exploit the natural parallelism in these networks.
phosphorous atoms are commonly added to parts of the silicon to increase conductivity.
A new silicon avalanche photodiode photon counting detector module for astronomy.
There has been a significant research effort in silicon photonics recently, both within the academic and industrial community.
The creation of an Asian Silicon Valley is itself inherently political.
For the most commonly used cut of silicon crystal, this angular range is approximately 3 micro radians.
The six silicon rectifiers face inwards to ensure efficient cooling without risk of terminal contamination.
The hologram is usually silicon plated with gold to make the surface reflective.
Silicon, with lower resistivity, also tends to operate at lower frequencies, in the ' Slow wave ' mode.
reversepan>reversing the polarity of the voltage, the atoms can be re-deposited anywhere on the silicon surface.
The 30 denier parachute ripstop nylon with silicon impregnation weighs only 1.35 oz per sq yard.
Fill any gaps in skirting boards with silicon sealant.
You will not be allowed to use silicon sealer.
Objects must not be held in place with adhesive or silicon sealer.
The current dominant silicon technology is CMOS - complementary metal oxide semiconductor.
Silicon carbide (Eg ~ 3 eV) has begun to establish itself as an effective wide band-gap semiconductor.
Its first major customer, a leading silicon semiconductor company.
Silicon gel sheeting has proven to be a safe and effective treatment too.
calcium oxide reacts with silicon dioxide to give calcium silicate.
Why does light create fewer electrical defects in some forms of hydrogenated amorphous silicon (a-Si:H) than others?
I doped silicon with several different group I and II impurities and measured their influence on the electrical and optical properties.
silicon based smart seal within the ear canal.
This suggests substituting alloys containing more silicon that the eutectic.
Behind the Solo is an amorphous silicon solar panel.
Amorphous silicon, a solid in which atoms are arranged in a non- periodic jumble, rivals crystalline silicon for photovoltaic applications.
My work is a novel study into the effects of incorporating antimony into strained silicon.
The indentation effect might even be at work in the way porous silicon (with a myriad of nanoscopic filaments) emits light.
pure silicon, another element in Group 4, has a similar structure.
silicon carbide can only be processed in powder form.
silicon wafer is then subjected to deep reactive ion etching to release the rotor.
silicon nitride block which has been damaged on the right side.
silicon micromachining, electro deposition and thin film metal and dielectric deposition.
silicon dioxide Silicon doesn't double bond with oxygen.
Alternatively, ribbons of silicon can be pulled from a melt of silicon to produce thin sheets of multicrystalline silicon.
Alternatively a block of polycrystalline silicon is sliced to produce the size of wafer required.
The finest pore metal foams can be made using silica micro balloons 100 or 30 microns across in aluminum silicon alloys.
High-power module (80W) using 125mm square multi - crystal silicon solar cells with 12.6% module conversion efficiency.
silicon carbide (used dry ).
Polytype coalescence in Lely vapor grown silicon carbide (SiC) has been studied extensively using the technique of X-Ray Diffraction (XRD ).
silicon carbide powders.
silicon carbide crystal shown by the extensive streaking evident along the diffraction rows.
silicon carbide coating, which can deliver high power while ensuring long piston life.
silicon carbide grains from meteorites (Anders and Zinner 1993) indicate characteristics of slow neutron capture reminiscent of AGB stars.
silicon carbide paper.
skirting boards with silicon sealant.
All because a few slivers of silicon refuse to accept the march of time.
slouching around in Silicon Valley.
These alpha particles were caused by the decay of thorium, a trace element in the silicon substrate.
She is now actively involved in using IBS to fabricate silicon based light emitting devices and to fabricate novel superconductors.
synchrotron X-ray diffraction patterns and to work out the diffractometer constants I refined a silicon pattern.
technological innovations ranging from lasers to silicon chips.
He explained: " What silicon has done for digital cameras, cadmium telluride wafers will do for x-ray signals.
If you add water to silicon tetrachloride, there is a violent reaction to produce silicon dioxide and fumes of hydrogen chloride.
CMOS, which stands for complementary metal oxide semiconductor, is the technology base for silicon transistors.
APS silicon hoses offer superior performance with regard to under bonnet heat soak than either steel or stainless steel tubing.
The 20-year veteran of the technology business is managing director of Wolfson, which supplies silicon chips used in DVD players and digital cameras.
Another test was with a very thin silicon wafer.
wafer foundries and fabrication houses to produce duplicates from silicon masters, significantly saving on production costs.
The silicon wafer is then subjected to deep reactive ion etching to release the rotor.
It enables coupling to thin (» 250nm) silicon waveguides.
I am analyzing synchrotron X-ray diffraction patterns and to work out the diffractometer constants I refined a silicon pattern.
Semiconductor detectors; types of semiconductor (silicon, germanium, cadmium telluride cadmium zinc telluride etc.
In addition to the above gaseous rectifiers of oscillations it has been found that several crystals, such as carborundum (carbide of silicon), hessite, anastase and many others possess a unilateral conductivity and enable us to rectify trains of oscillations into continuous currents which can affect a telephone.
Thus, hydrogen unites with but a single atom of chlorine, zinc with two, boron with three, silicon with four, phosphorus with five and tungsten with six.
Weber, who showed that with rise of temperature the specific (and atomic) heat increases, finally attaining a fairly constant value; diamond, graphite and the various amorphous forms of carbon having the value about 5.6 at mooÃ‚°, and silicon 5.68 at 232Ã‚°; while he concluded that boron attained a constant value of 5.5.
The product is a crystalline solid of specific gravity 2.34, and melts at about 1430Ã‚° C. See also German Patent 108817 for the production of crystallized silicon from silica and carborundum.
The specific heat varies with the temperature, from 0.136 at -39Ã‚° C. to 0.2029 at 232Ã‚° C. Silicon distils readily at the temperature of the electric furnace.
Ruff and Curt Albert (Ber., 1905, 38, p. 53) by decomposing titanium fluoride with silicon chloroform in sealed vessels at 100 -120Ã‚° C. It is a colourless gas which may be condensed to a liquid boiling at -80 2Ã‚° C. On solidification it melts at about -110Ã‚° C. The gas is very unstable, decomposing slowly, even at ordinary temperatures, into hydrogen,, silicon fluoride and silicon: 4SiHF 3 =2H 2 +3SiF 4 +Si.
Silicon nitrogen hydride, SiNH, is a white powder formed with silicon amide when ammonia gas (diluted with hydrogen) is brought into contact with the vapour of silicon chloroform at -10Ã‚° C. Trianilino silicon hydride, SiH (NHC 6 H 5) 3, is obtained by the action of aniline on a benzene solution of silicon chloroform.
It crystallizes in needles which decompose at "4Ã‚° C. Silicon amide, Si(NH 2) 4, is obtained as a white amorphous unstable solid by the action of dry ammonia on silicon chloride at -50Ã‚° C. (E.
Silicon tetraphenyl, Si(C6H5)4, a solid melting at 231Ã‚° C., is obtained by the action of chlorobenzene on silicon tetrachloride in the presence of sodium.
OH, formed by the action of moist air on silicon octochloride at oÃ‚° C., is very unstable, and hot water decomposes it with evolution of hydrogen and formation of silicic acid (L.
It is a colourless solid which melts at 92Ã‚° C. For silicon derivatives of the amines see Michaelis, Ber., 1896, 29, p. 710; on asymmetric silicon and the resolution of dl-benzyl-ethyl-propyl-silicol see F.
What is known as cast iron is essentially an alloy of iron proper with 2 to 6% of carbon and more or less of silicon (see Iron).
About 1840 he was engaged in experiments by which he sought to prove that "carbon in certain states of combination is susceptible of conversion into silicon," and his failure to establish this proposition had much to do with his want of success as a candidate for the chair of chemistry at Edinburgh in 1843.
It is a most powerful oxidizing agent, phosphorus being readily oxidized to phosphoric acid, arsenic to arsenic acid, silicon at 250Ã‚° C. to silica, and hydrochloric acid to chlorine and water.
At high temperatures it acts as a reducing agent, reducing silica to silicon, boric acid to boron, &c. (H.
by first putting carbon and silicon into the iron and then taking them out again at great expense, at first sight seems so unreasonably roundabout that many " direct " processes of extracting the iron without thus charging it with carbon and silicon have been proposed, and some of them have at times been important.
In the Bessemer or " pneumatic" process, which indeed might be called the " fuel-less " process, molten pig iron is converted into steel by having its carbon, silicon and manganese, and often its phosphorus and sulphur, oxidized and thus removed by air forced through it in so many fine streams and hence so rapidly that the heat generated by the oxidation of these impurities suffices in and by itself, unaided by burning any other fuel, not only to keep the iron molten, but even to raise its temperature from a point initially but little above the melting point of cast iron, say 1150 to 1250Ã‚° C., to one well above the melting point of the resultant steel, say i soo C. The " Bessemer converter " or " vessel " (fig.
If the carbon-content is not to be raised materially, this manganese is added in the form of preheated lumps of " ferro-manganese," which contains about 80% of manganese, 5% of carbon and 15% of iron, with a little silicon and other impurities.
In the Bell-Krupp or "pig-washing" process, invented independently by the famous British iron-master, Sir Lowthian Bell, and Krupp of Essen, advantage is taken of the fact that, at a relatively low temperature, probably a little above 1200Ã‚° C., the phosphorus and silicon of molten cast iron are quickly oxidized and removed by contact with molten iron oxide, though carbon is thus oxidized but slowly.
It combines with fluorine with incandescence at ordinary temperatures, and with chlorine at 250-300Ã‚°; carbon, silicon, and boron, when heated with it in the electric furnace, give crystals harder than the ruby.
Elements like phosphorus and silicon react with the oxygen to form acidic oxides.
By reversing the polarity of the voltage, the atoms can be re-deposited anywhere on the silicon surface.
Cement contains up to 5% silica in the form of free silicon dioxide which causes lung scarring known as silicosis.
Calcium oxide reacts with silicon dioxide to give calcium silicate.
The concept removes the need for a custom made ear mold by utilizing a flexible silicon based smart seal within the ear canal.
Pure silicon, another element in Group 4, has a similar structure.
The structure of silicon dioxide Silicon does n't double bond with oxygen.
When dry, sand the surface smooth with a sanding block using 80 grit silicon carbide (used dry).
Polytype coalescence in Lely vapor grown silicon carbide (SiC) has been studied extensively using the technique of X-Ray Diffraction (XRD).
One surface is then lapped using liquid suspensions of successively finer silicon carbide powders.
Figure 8. A good example of a highly disordered silicon carbide crystal shown by the extensive streaking evident along the diffraction rows.
Isotopic analysis of silicon carbide grains from meteorites (Anders and Zinner 1993) indicate characteristics of slow neutron capture reminiscent of AGB stars.
Mounted specimens are ground with rotating disks of abrasive paper, for example wet silicon carbide paper.
What I do sense is that some new Rough Beast Operating System is even now slouching around in Silicon Valley.
The NanoTest was used to investigate diamond-like carbon films on silicon which were prepared by magnetron sputtering from a graphite target.
I am analyzing synchrotron x-ray diffraction patterns and to work out the diffractometer constants I refined a silicon pattern.
Quantum mechanics also provides the basis for technological innovations ranging from lasers to silicon chips.
Mother pieces " waxed " down to a silicon carrier using a thermoplastic polymer.
After the silicon vertex detector is the Central Outer Tracker, a gas drift chamber which operates via the detection of charged ions.
Use sparingly to care for your glove, and be sure the cream does not contain silicon.
You'll also need to have either a no-stick baking sheet or have a silicon sheet or foil to cover a baking sheet.
Silicon is a naturally-occurring element that, when compounded with oxygen, forms silicon dioxide (also known as silica).
Using silicon or another form of semi-conductor, solar panels convert light into energy by creating a flow of electrons and a magnetic field.
This current must then be guided out of the cell in order to harness the potential energy created when the sun's energy freed the electrons in the silicon semi-conductor.
Most solar shingles use crystalline silicon because it is the most economically feasible material to use.
They are devised of silicon and other materials and are attached to a building's roof.
It was the worlds first "solar battery" using silicon solar cells, but the materials used and the manufacturing procedures required to build it made the device far too expensive to be practical.
Photovoltaic cells, also known as PV or solar cells, are created from semiconductor material such as silicon.
Modern PV technology is called "thin-film silicon photovoltaics," and most experts within alternative energy industries consider it as the fastest growing energy technology.
They are made of a light type of silicon coating that is applied in thin layers and that acts as a conductor.
The sun hits the silicon and is absorbed by it.
They use three different layers of silicon in a flexible base, calling it a triple junction cell.
Silicon Solar - Silicon Solar specializes in build your own solar kits.
When sunlight hits the photovoltaic cells of the panels, a silicon semiconductor absorbs a percentage of the energy and turns it into a current of electricity.
Monocrystalline panels are manufactured from a large silicon crystal.
Instead of one large silicon crystal, multiple smaller crystals make up polycrystalline panels.
Amorphous panels are made of a thin film of molten silicon spread across plates of stainless steel.
By using a method called photovoltaics, researchers found they can generate electrical power by funneling the sun through a specific medium like copper or silicon to harness the energy from solar radiation.
Tony, Daniel, and Brad all grew up in this suburb of the Silicon Valley area and began their interest in filmmaking at a very young age.
Plus, with his work in Silicon Valley and Wall Street, he has a lot of experience in all types of businesses, so he has been there for advice and the introduction to various contacts.
You can easily use silicon bake ware as molds, and they come in hearts, flowers and other fun shapes you might like.
Visit Silicon Solar for more information.
Head and facial contours - A nasal or full face mask is rigid in construction and relies on soft silicon nasal cushions to fit tight against your face to form a tight seal.
Mask cushion- The gel mask cushion can be replaced when the silicon softens, causing air leaks at the top of the mask.
The silicon in the mask will become softer which will, in turn, keep the mask from forming an airtight seal on the face.
Replace your mask frequently - The silicon in a nasal mask will start to break down after about six to nine months, becoming soft and causing the mask to leak.
The "0" Degrees pair features 100% hypoallergenic optically glazed frames with spring hinges, silicon nose pads and a CR-39 polarized lens.
This coating is frequently made from zircon and silicon.
These metals include aluminum combined with some silicon and iron to add strength.
The California-based company was formed in 1991 under the name Silicon and Synapse by Mike Morhaime, Frank Pearce and Allen Adham.
While the bunnies of Playboy may sometimes be enhanced, this issue's women are all-digital and all silicone… um, I mean silicon.
If you want to have covers that match the clear covers for the Wiimote, then purchase an official Wii Fit Balance Board cover made from silicon material.
However, the region is somewhat of an oddity being in the hills just a stone throw away from Silicon Valley.
Artifacts: An Archaeologists Year in Silicon Valley by Christine A.
Silicon is important in preventing cardiovascular disease.
Once the ponytail is formed and secured with an elastic or silicon band, twist the hair sleekly.
This cool climate wine region includes the Santa Cruz Mountains north of Monterey and has a few wineries in the hills straddling the Pacific and Silicon Valley.
Other ingredients include potato starch, gelatin, and silicon dioxide.
Moissanite is a rare mineral with a hexagonal crystal structure that occurs in iron-nickel meteorites and may also be called silicon carbide or carborundum in reference to its chemistry.
This silicon spray (available at most shoe stores) should be applied before you even wear your shoes outside.
It is comprised of silicon dioxide and is used as an additive which absorbs excess liquid in some foods.
This has proved to be erroneous; it is non-metallic in character, and its name was altered to silicon, from analogy with carbon and boron.
The specific heats of carbon, boron and silicon subsequently formed the subject of elaborate investigations by H.
Wohler, he investigated the allotropic forms of silicon and boron.
SILICON [[[symbol]] Si, atomic weight 28.3 (0=16)], a nonmetallic chemical element.
Amorphous silicon is a.
It burns with a pale-blue flame forming silicon fluoride, silicofluoric acid and silicic acid.
It is then dissolved in hydrofluoric acid and heated in order to expel silicon fluoride; finally the columbium, tantalum and titanium fluorides are separated by the different solubilities of their double fluorides (C. Marignac, Ann.
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