Effects of the third additional elements on rapid cooled cast structures of Al-3∼5% Mn alloys

Abstract

Cooling conditions for easily obtaining the network microstructure of primary crystallized supersaturated α-solid solution, which was observed only by rapid cooling from the molten bath, were researched on ternary Al-3∼5% Mn base alloys. Mechanical properties of the alloys having such structure were also studied. The results obtained were as follows: (1) Cooling velocity of more than 900°C/sec. between 800°C and m.p. was indispensable for obtaining such network structure on binary Al-3∼4% Mn alloys, but the limit of the velocity was dropped to 250∼300°C/sec. on Al-3% Mn alloys containing a suitable amount of Ag, Cu, Mg, Si, or Zn. (2) The critical cooling velocity of the ternary alloys containing Fe, Ni, and Ti was almost the same as that of binary alloys. (3) Favorable data of tensile strength and elongation were observed on ternary alloys having such structure. © 1966, The Japan Institute of Light Metals. All rights reserved.