786 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Binary Alloys of Cobalt.* — K. Lewkonja has determined the 

 equilibrium diagrams and studied the magnetic properties and structure 

 of the alloys of cobalt with the nine elements named below. Cobalt 

 is miscible with tin and also with antimony, in all proportions in the 

 liquid state. The compounds are Co 2 Sn, CoSn, CoSb, and CoSb.,. 

 With lead, bismnth, and thallium, cobalt is miscible in the liquid state 

 only to a small extent, the molten alloys separating into two layers 

 except for short ranges at both ends of each system. The cobalt-zinc 

 system was studied only in the range 0-18 " 5 p.c. cobalt. The exist- 

 ence of CoZn 4 is probable. Cobalt and chromium are mutually soluble 

 in all proportions in the liquid and solid states. Cobalt and silicon are 

 miscible in all proportions in the liquid state, and form five compounds. 

 The diagram for the cobalt-cadmium system is incomplete. The 

 results now available concerning the binary alloys of iron, of nickel, 

 and of cobalt are carefully analysed and summarised in tabular form. 



Manganese and Carbon.t — A. Stadeler has made a thermal and 

 microscopic study of manganese and its alloys with carbon. The 

 melting-point of the purest commercial manganese obtainable (9G p.c.) was 

 found to be 1207° C. No evidence of allotropic modifications was 

 obtained. The saturation point of carbon in manganese is 6*72 p.c, 

 corresponding to Mn 3 C. The solidification point curve rises to 1271° C. 

 at 3*32 p.c. carbon, then falls to 1217° C. at 6*72 p.c. From 0'72- 

 3 • 60 p.c. a critical point at 817-855° C. was found. Manganese probably 

 forms with Mn 3 C a series of mixed crystals which is continuous above 

 855° C. At lower temperatures, in the range 0-3 • 6 p.c. carbon, two 

 series of solid solutions exist. Cementation of manganese with carbon 

 does not appear to be possible. 



Alloys of Zinc, Copper, and Nickel4 — V. E. Tafel has determined 

 the equilibrium diagrams for the three binary systems and partially for 

 the ternary system zinc-copper-nickel. The microstructure of the 

 alloys was also studied. The diagrams given by Guertler and 

 Tammann for the copper-nickel system, and by Shepherd for the 

 copper-zinc system, are, on the whole, confirmed. In the zinc-nickel 

 system the compound NiZn 3 (melting-point 876° C), and two series of 

 mixed crystals containing respectively 12 • 2-23 '0 p.c. and 39" 7-49*0 

 p.c. nickel were found. The constitution of other phases is uncertain. 

 The range 0-50 p.c. nickel only was studied, as zinc-nickel alloys with 

 more nickel could not be prepared. The ternary system is very com- 

 plex. No ternary compound or ternary eutectic was found. 



Copper-arsenic System.§ — Considerable differences between the 

 diagram given by Hiorns and that determined by K. Friedrich, have led 

 the latter to carry out a further investigation. The author's results 

 were confirmed in essential points. The compounds are Cu 5 As 2 and 

 Cu 3 As. Evidence for Cu 2 As was not obtained. Copper may contain 



* Zeitschr. Anorg. Chem.,lix. (1908) pp. 293-345 (41 figs.), 

 t Metallurgie, v. (1908) pp. 260-7, 281-8 (52 figs.). 

 J Tom. cit., pp. 343-52, 375-83, 413-30 (100 figs.). 

 § Tom. cit., pp. 529-35 (16 figs.). 



