Effect of extrusion process on microstructure and mechanical properties of Ni3Al−B−Cr alloy during self-propagation high-temperature synthesis
(1. PKU-HKUST Shenzhen−Hong Kong Institution, Shenzhen 518057, China;
2. College of Engineering, Peking University, Beijing 100871, China;
3. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
2. College of Engineering, Peking University, Beijing 100871, China;
3. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract: The well-densified Ni3Al−0.5B−5Cr alloy was fabricated by self-propagation high-temperature synthesis and extrusion technique. Microstructure examination shows that the synthesized alloy has fine microstructure and contains Ni3Al, Al2O3, Ni3B and Cr3Ni2 phases. Moreover, the self-propagation high-temperature synthesis and extrusion lead to great deformation and recrystallization in the alloy, which helps to refine the microstructure and weaken the misorientation. In addition, the subsequent extrusion procedure redistributes the Al2O3 particles and eliminates the γ-Ni phase. Compared with the alloy synthesized without extrusion, the Ni3Al−0.5B−5Cr alloy fabricated by self-propagation high-temperature synthesis and extrusion has better room temperature mechanical properties, which should be ascribed to the microstructure evolution.
Key words: Ni3Al intermetallic compound; self-propagation high-temperature synthesis; extrusion; microstructure; mechanical properties