METALLURGY. 



483 



color has become uniform and the mass homo- 

 geneous, sulphurous acid begins to escape. 

 The paste is wrapped in paper and thrown 

 into a crucible heated to redness, so as to de- 

 compose the petroleum. The flame is allowed 

 to escape and the crucible is cooled. The com- 

 pact product obtained having been powdered 

 and mixed with an equal weight of a metal in 

 powder, is placed in a graphite crucible, which 

 is well closed and heated to whiteness. In 

 the black powder which is observed when the 

 cooled crucible is opened, are found grains 

 and alloys of aluminum. This process is also 

 applicable to silica, lime, magnesia, etc. 



The "Colossus" dynamos of the Cowles 

 works at Lockport, N. Y., the operation and 

 efficiency of which were described in the " An- 

 nual Cyclopaedia" for 1886, are now at work, 

 and producing the pure metal and its useful 

 alloys and bronzes in large quantities daily. 



For electro-plating with aluminum, Mr. Her- 

 man Reinhold recommends a mixture consist- 

 ing of a solution of 50 parts of alum in 300 

 parts of water, with 10 parts of chloride of 

 aluminum to which, after heating to 200 and 

 cooling, 39 parts of cyanide of potassium are 

 added. The object to be plated, having been 

 cleaned and freed from all forms of grease, is 

 suspended in the bath over the electro-positive 

 anode, while the plate of metallic aluminum is 

 suspended on the negative pole. 



In a specimen of what is called aluminum 

 steel, exhibited by the Cowles Electric Smelt- 

 ing and Aluminum Company, a sample bar of 

 iron welded to a band of Siemens-Martin basic 

 steel with 0'2 per cent, of aluminum added, 

 shows no line of weld, and the characteristics 

 of the steel appear to extend far into the iron. 

 Without the aluminum, a clearly defined weld 

 is visible between iron and the same steel. 



Alloys. A number of metallic alloys have 

 been prepared by H. Warren by an electrolytic 

 method which differs slightly from the manner 

 in which mercury combines with other ele- 

 ments by reason of the liquidity of mercury. 

 On substituting for the mercury, iron, copper, 

 zinc, etc., these metals may be readily made to 

 combine with the more oxidizable elements, 

 such as silicon, phosphorus, etc., by so arrang- 

 ing the process that the metal employed for 

 forming the alloy, when in a fluid state, is 

 connected with the negative pole of a voltaic 

 series, and is in direct contact with the sub- 

 stance containing the element with which it is 

 desired to combine it. A silicon bronze was 

 produced by this method by the electric action 

 on metallic copper and silico-fluoride. Phos- 

 phor and other bronzes may also be readily 

 formed in a similar manner. For the prepara- 

 tion of silicon-eisen the substitution of iron 

 for copper is all that is required. The silicon- 

 eisen so obtained presents the appearance of 

 hot-blast silicon. Native cryolite may be read- 

 ily decomposed when in contact with metallic 

 zinc, and by suitable means the zinc may be 

 volatilized, leaving pure aluminum. 



It is remarked by Thomas D. West that 

 the difficulties which beset the casting of alu- 

 minum bronze are, in some respects, similar to 

 those which were encountered in perfecting 

 methods for casting steel. There is much 

 small work which can be successfully cast by 

 methods used in the ordinary moldings of 

 cast-iron; but in peculiarly proportioned, and 

 in large bronze castings, other means and extra 

 display of skill and judgment will be generally 

 required. In strong metals there appears to 

 be a " redshortness " or degree of temperature, 

 after the material becomes solidified, at which 

 it may be torn apart, if it meets a very little 

 resistance in its contraction ; and the separa- 

 tion may be such as can not be detected by the 

 eye, but will be made known only when press- 

 ure is put upon the casting. To overcome this 

 evil, and to make allowances for sufficient 

 freedom in contraction, much judgment will 

 often be required, and different modes must be 

 adopted to suit varying conditions. One fac- 

 tor often met with is that of the incompressi- 

 bility of cores or parts forming the interior 

 portion of castings, while another is the re- 

 sistance which flanges, etc., upon an exterior 

 surface, oppose to the freedom of contraction 

 of the mass. The author has combated the 

 former difficulty by mixing resin and sand in his 

 cores, or using " green-sand " cores. In cast- 

 ings requiring large round cores, which could 

 be "swept," a hay-rope wound around a core 

 barrel would often prove an excellent backing, 

 and allow freedom for contraction sufficient to 

 insure no rents or invisible strain in the body 

 of the casting. To provide means for freedom 

 in the contraction of exterior portions of cast- 

 ings which may be supposed to offer resistance 

 sufficient to cause an injury, different methods 

 will have to be employed in almost every new 

 form of pattern. One method found to work 

 well is to " gate " a mold so that it can be filled 

 or poured as quickly as possible, and to have the 

 metal as dull as it will flow to warrant a full- 

 run clean casting. Aluminum bronze is free 

 from the "blow-holes" which are liable to 

 exist in strong metals. 



The alloy of nickel, copper, and aluminum, 

 known as lechesne, is recommended as com- 

 bining absolute malleability with an excep- 

 tional degree of homogeneity, tenacity, and 

 ductility, and as having less liability to oxi- 

 dize and act as a heat-conductor than other 

 alloys heretofore in use. Its distinctive feat- 

 ure consists in the addition to the binary al- 

 loy (nickel and copper) of a quantity of alumi- 

 num, calculated according to the proportion 

 ' of the nickel. Like gold, silver, and platinum, 

 the lechesne alloy satisfies the conditions of the 

 most difficult processes of hammering, draw- 

 ing, and deep chasing or punching, especially 

 in'ornamental work. It is employed for the 

 production of a superior kind of German-silver. 



A new alloy has been discovered by Mr. 

 Reith, of Bockenheim, which practically re- 

 sists the attack of most acids and alkaline solu- 



