Microstructure and mechanical properties of 2024Al-Fe-Ni PM alloys consolidated by equal channel angular pressing

Experiments were conducted on 2024Al-3mass%Fe-5mass%Ni (3F5N) alloy powder to investigate the feasibility of the producing a compaction with very homogeneous fine microstructure using equal-channel angular (ECA) pressing and of forging the compaction superplastically. It is shown that ECA pressing is capable of obtaining the compaction almost without pores and with very high hardness even after single pressing. Repetitive pressings were conducted on the same samples, up to a total of 3 passages through a die, with the samples pressed without rotation (R=0 deg) and after rotating through 90 deg or 180 deg between each pressing. The results suggest that, ECA pressing with R=90 deg rotation is most effective in producing a reasonably homogeneous microstructure consisted of fine intermetallic particles and equiaxed fine subgrains, and such microstructure formation could contribute to the superplastic-like deformation behavior at high strain rate.