Fabrication of submicron NiAl-Al₂O₃ composite and its sinter-forging with short process

Taking Ni and Al powders as raw materials, NiAl-5vol% Al₂O₃ composite was prepared by mechanical alloying and hot-pressed sintering, and a model of leading edge was subsequently fabricated by sinter-forging process. By mechanical alloying, the powders were refined and NiAl-5vol%Al₂O₃ was synthesized through in-situ reaction. Dense NiAl-Al₂O₃ composite was consolidated through hot-pressed sintering at 1300°C. It was observed that Al₂O₃ particles homogeneously distributed in NiAl matrix in the form of "intragranular structure" and "intergranular structure". The average sizes of NiAl and Al₂O₃ are 400 nm and 100 nm respectively. Compared with fine grained NiAl, the fracture toughness and compression performance are both obviously improved. The leading edge was fabricated by sinter-forging process, which is characterized by fine grains and high surface quality, and its Vickers hardness is up to 575HV.