540 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



referred to the cored structure of ancient Egyptian bronzes, in which 

 recrjstaUization, but not diffusion, appeared to have occurred in the 

 course of some thousands of years at ordinary temperatures. 



Heat-treatment of Gun-metal.* — H. S. Primrose and J. S. G. 

 Primrose describe experiments upon Admiralty gun-metal containing 

 88 p.c. copper, 10 p.c. tin, 2 p.c. zinc, the results of which indicate that 

 the mechanical properties may be much improved by an annealing (e.g. 

 at 700° C), which causes the disappearance of the S-containing eutectoid. 

 The annealed alloy consists solely of the a solid solution. Twenty-four 

 photomicrographs illustrate the structure of the alloy after different 

 heat-treatments. 



Brasses containing Nickel. f — L. Guillet gives a more complete 

 account of the determination of the " coefficient of equivalence " of 

 nickel when added to copper-zinc alloys, and describes the microstructure 

 of two series of alloys containing respectively 49 and 55 p.c. copper. 

 The nickel ranged from to 10 p.c, and the remainder was zinc. 

 Comparison between the structures of the alloys as cast, and after 

 annealing for two hours at 750° C, indicated that annealing was essential 

 in order to secure homogeneity in structure. In the alloy containing 

 49 p.c. copper, 10 p.c. nickel, cast in sand, the (3 constituent possessed 

 a most distinct eutectoid structure. Acid ferric chloride solution was 

 used for etching. 



Permanence of Structure in Copper-zinc Alloy. | — A. K. Huntington 

 describes the structure of copper-zinc alloy stays from the fire-box of a 

 locomotive. In sixteen years of use the stays had been subjected to 

 varying temperatures, and to constant vibration and stresses. The cored 

 a + /3 structure was practically identical with that of a freshly-prepared 

 ingot, and indicated that diffusion or recrystallization had not occurred. 



Copper-antimony Equilibrium. § — H. C. H. Carpenter, in the course 

 of a complete revision of the copper-antimony equilibrium, has relied 



Constitution 



Solid solution of CuaSb in copper 



Its basis is the compound CujSb 



The compound Cu^Sb 



Almost pure antimony 



Colour 

 Golden brown 

 Greenish grey 

 Purple lilac 



White . . . . 



Atomic percentage 

 Copper 



100 to 96 



96 to 81 



81 to 75 



75 to 66-6 



66-6 



66 • 6 to about 1 



Not more than 1 



* Journ. Inst. Metals, ix. (1913, 1) pp. 158-86 (33 figs.). 



t Bev. M6tallurgie, x. (1913) pp. 1130-41 (20 figs.). 



X Journ. Inst. Metals, ix. (1913, 1) pp. 39-41 (6 figs.). 



§ Int. Zeitschr. Metallographie, iv. (1913) pp. 300-22 (15 figs.). 



