356 



METALLURGY. (COPPER, NICKEL, TIN, AND Zixc.) 



it is the cost of one third of a pound of it that 

 is to be compared with the cost of one pound 

 of them. The labors of metallurgists in searching 

 for light strong alloys of aluminum are bearing 

 fruit in abundance. Aside from its color, alumi- 

 num resembles copper in many of its qualities, and 

 especially in that both metals are soft and rather 

 weak, susceptible of being greatly hardened when 

 alloyed. Five per cent, of copper, nickel, or man- 

 ganese or 30 per cent, of zinc. added to aluminum 

 make strong metals as rigid as bronze, yet only 

 one third as heavy. Such light, strong, good 

 casting and machining alloys have an extremely 

 large field of usefulness. An alloy principally of 

 aluminum and zinc, selling at the same price per 

 pound as pure aluminum, is hard and white, of 

 specific gravity 3.1, melts clean, runs fluid, makes 

 beautifully sharp and perfect castings, turns and 

 machines like the finest brass, polishes well, and 

 is fully as strong as gun metal or the best of 

 the ordinary bronzes. The use of aluminum for 

 culinary utensils is extending steadily. These 

 vessels are described as possessing all the advan- 

 tages of copper utensils, with none of their dis- 

 advantages. They need only as much attention as 

 ordinary tinware to keep them bright and clean. 

 Aluminum, on account of its harmlessness, is su- 

 perseding zinc for fruit-jar caps. It is winning an 

 important place in the artistic branch of litho- 

 graphic printing, for which aluminum plates offer 

 considerable advantages over lithographic stone. 

 Electric conductors can now be laid more cheaply 

 in aluminum than in copper. While the aluminum 

 wire has, in order to give equal conductivity, to 

 be one fourth as large again in diameter as a 

 wire of copper, it weighs only one half and costs 

 only two thirds as much as the copper wire it 

 replaces. Long-distance transmission lines and 

 trolley feed wires are being set up in aluminum 

 as fast as the makers can supply the metal. Alu- 

 minum can be rolled out to ^tiVff f an inch in 

 thickness, and then beaten out to ^Vir or even 

 T-fav of an inch. As thin sheet it has found some 

 application in place of cardboard for business 

 cards, etc., but as leaf it has entirely superseded 

 silver leaf in decorating. This leaf can be ground 

 to powder, and in that condition is used by print- 

 ers for silvery printing, and as a paint. For the 

 latter use it is simply mixed with a varnish like 

 ordinary bronzing powders. Powdered aluminum 

 has recently received an extremely interesting 

 metallurgical application in the reduction of re- 

 fractory metallic oxides to the metallic state. 



In a paper on the same subject, also in the 

 Franklin Institute, Mr. J. A. Steinnetz undertook 

 to enumerate the uses of aluminum that have 

 proved satisfactory and extensive, with a view of 

 encouraging further applications along kindred 

 lines, and to speak words of caution regarding 

 improper uses of the metal. His list of useful 

 applications includes those mentioned by Prof. 

 Richards and some others, among which are the 

 making of patterns, for which, when stiffened by 

 the addition of about 5 per cent, of zinc and a 

 like amount of copper, aluminum forms an ex- 

 cellent substitute tor brass, with the advantage 

 of the great difference in weight, and for models 

 and salesmen's samples. At the author's sugges- 

 tion it had been used instead of wood for making 

 models for castings, with excellent results in free- 

 dom from defects to which wooden models are 

 liable. It has been, found an excellent material for 

 making steam-jacketed kettles and caldrons for 

 boiling fruit juices, honey, and wax, and for certain 

 acid work for which the peculiar qualities of the 

 metal well adapt it. But it is not suitable for 

 bath tubs and plumbing fixtures or for any pur- 



poses in which it is exposed to the action of the 

 alkali of soaps. In the powdered condition alumi- 

 num furnishes an excellent material for photo- 

 graphic flash lights, being cheaper than magne- 

 sium powder and free from the unpleasant smoke 

 that accompanies the use of that metal. 



The principle underlying a new method of pro- 

 ducing high temperatures, described by Mr. E. F. 

 Lange at the autumnal meeting of the Iron and 

 Steel Institute, is based upon the heat energy 

 developed by the chemical action of aluminum 

 upon oxygen, or that between aluminum and cer- 

 tain metallic oxides. The practicability of the 

 process was shown by the welding together during 

 the meeting of two short lengths of heavy girder 

 rails. Besides opening up another field for alumi- 

 num, the new method promises to be of consider- 

 able importance in engineering work. In the dis- 

 cussion of Mr. Lange's paper, Sir W. C. Roberts- 

 Austen pointed out the extreme precision with 

 which the reduction took place, and Sir Lowthian 

 Bell dwelt on the value of the process if it should 

 prove that carbonless iron could be obtained by 

 it for electrical purposes. 



Metallurgy by means of secondary electrical fur- 

 naces is the name which Herr Goldschmidt, of 

 Essen, has given to a process of reduction by alumi- 

 num for which no extraordinary heat is required. 

 It has been found useful in the preparation of 

 metals employed in the manufacture of special 

 varieties of steel. In the preparation of metallic 

 manganese, for instance, the binoxide of that 

 metal is mixed with pulverized aluminum, a sub- 

 stance capable of deoxidizing it and setting the 

 metallic manganese free. The reaction is brought 

 about whenever any point of the mixture is raised 

 to the temperature of ignition, and will go on of 

 itself, just as in the case of a mixture of oxygen 

 and hydrogen, or of an explosion of gunpowder, 

 without its being necessary to make any further 

 application of heat. In the process of abstracting 

 oxygen from the metallic oxide, the aluminum 

 disengages a considerable quantity of heat, and the 

 mass under treatment is raised to a dazzling white 

 so that the aluminum oxide melts into a mobile 

 liquid, while the melted manganese collects in the 

 bottom of the crucible. A temperature is reached 

 approaching that of the electrical furnace. Besides 

 manganese, chromium, tungsten, molybdenum, and 

 vanadium have been prepared within a few months 

 through the reduction of their oxides by alumi- 

 num. By virtue of the character of the process, 

 metals thus prepared are absolutely free from car- 

 bon, a feature of great value in their application 

 to the improvement of steel. In this they have 

 a distinct advantage over the same metals pre- 

 pared in the electrical furnace which contain car- 

 bon. Besides metals available for use, the second- 

 ary electrical furnace furnishes aluminum oxid<> 

 in the form of a very hard corundum or emery. 

 which is sold for a polishing and grinding powder. 

 The high temperature of the reactions in HIM 

 process can be applied to the soldering and brazing 

 of metals. Easily reducible oxides, like those of 

 lead and copper, give explosive reactions with 

 aluminum. 



Copper, Nickel, Tin, and Zinc. The electro- 

 deposition of copper is now carried on, according 

 to Mr. Sherrard Cowper-Coles, in many l.uirc ci - 

 gineering works for the production of largo copper 

 vessels. Most of the copper used by electric;! 

 engineers, and more than one third of the tot: 1 

 copper output of the world, is now electrolyticallp 

 refined. The demand for electrolytic copper is on 

 the increase, and the capacity of most of the ele<!- 

 InMytic refining works has been or is being en- 

 larged. According to estimates published in In- 



