VIII. The constitution of the alloys of aluminium and zinc

Abstract

The alloys of aluminium and zinc have been studied as regards their constitution by Heycock and Neville, Shepherd, and Ewen and Turner. The present authors having occasion to study these alloys from the point of view of their mechanical and physical properties in a research carried out under the auspices of The Alloys Research Committee of the Institution of Mechanical Engineers, began by accepting the equilibrium diagram in which Shepherd had expressed the results of his investigation. A few cooling-curves, however, which were taken in the first place with the object of confirming shepherd's results, immediately showed that the constitution of these alloys must be much more complex than had been supposed by Shepherd. It therefore seemed desirable to carry out a more complete investigation on the constitution of these alloys, and the results of that investigation are presented in the present paper. The materials used in the present investigation were : aluminium of a high degree of purity, kindly presented by the British Aluminium Company, and a very pure variety of zinc, kindly presented by Sir John Brunner. The analyses of these materials are as follows :— Aluminium— Silicon ..........................................0T7 percent. Iron ...............................................0'20 ,, Copper...................................Trace. Aluminium (diff.)......................99˙63 per cent. Zinc— The zinc used contained traces only of iron and silicon, and was of at least 99˙98 per cent, purity.