Microstructure and properties of β-NiAl and its eutectic alloy with Cr and Mo additions
(1.北京市北京航空航天大学材料科学与工程学院
2.School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,
3.School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,Beijing 100083, China)
2.School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,
3.School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,Beijing 100083, China)
Abstract: NiAl-0.3Ru and NiAl-30Cr-4Mo alloys were fabricated by arc melting method and then annealed at 1 423 K for 12 h. It has been revealed that NiAl-0.3Ru was in a single-phase with large grain size and NiAl-30Cr-4Mo consisted of multiple eutectic cells. Each cell consisted of alternating plates NiAl and Cr(Mo). The compressive properties including the brittle-ductile transition temperature (BDTT) were tested. NiAl-0.3Ru and NiAl-30Cr-4Mo fractured with a little plastic deformation after yielding below the BDTT, and almost no fracture was found after large deformation up to 60% above the BDTT. Fractograph showed that at the room temperature, the fracture in NiAl-0.3Ru was intergranular and the NiAl-30Cr-4Mo in transgranular along the interface between b-NiAl and Cr (Mo). The compressive properties of NiAl were obviously improved by eutectic alloying with Mo and Cr additions.
Key words: β-nickel aluminide; eutectic alloy; compressive properties; brittleness; ductility; fracture morphology