Powder metallurgy Al-6Cr-2Fe-1Ti alloy prepared by melt atomisation and hot ultra-high pressure compaction

Al-6Cr-2Fe-1Ti alloy was prepared by melt atomisation into rapidly solidified powder. The powder was compacted using uniaxial hot compression at an ultra-high pressure (6 GPa). The samples were pressed at 300, 400 and 500 C. The structure, mechanical properties and thermal stability were examined and compared with those of the commercially available Al-12Si-1Cu-1Mg-1Ni casting alloy, which is considered thermally stable. It was shown that the hot compression at ultra-high pressure results in a compact and pore-free material with excellent mechanical properties. The elevated pressing temperatures were found to be effective at increasing the mechanical stability after applying the ultrahigh pressure. The results of thermal stability testing revealed that the mechanical properties do not change significantly at high temperature, even after 100 h of annealing at 400 degrees C. In addition, the Al-6Cr-2Fe-1Ti alloy exhibited very good creep resistance. A comparison between the commercial Al-6Cr-2Fe-1Ti alloy and the powder metallurgy alloy shows that this alloy has significantly better mechanical properties and thermal stability. (C) 2012 Elsevier B.V. All rights reserved.