Microstructure and properties of β-NiAl and its eutectic alloy with Cr and Mo additions

• Published in: Transactions of Nonferrous Metals Society of China Vol. 16; no. A03; pp. 2046 - 2049
• Main Author: 张志刚 刘先斌 宫声凯 徐惠彬
• Format: Journal Article
• Language: English
• Published: School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China 01.12.2006
• Subjects: 微观结构; 机械性能; 物理属性; 镍合金; β-nickel aluminide; eutectic alloy; brittleness; ductility; compressive properties; fracture morphology
• ISSN: 1003-6326

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 fiNiAl and Cr （Mo）. The compressive properties of NiAl were obviously improved by eutectic alloying with Mo and Cr additions.