利用激光熔化沉积技术制备出分别以NiTi和Ni3Ti为初生相的NiTi/Ni3Ti金属间化合物耐磨合金,采用XRD、OM、SEM、EDS等手段分析合金的组织,测试合金的室温干滑动磨损性能。结果表明,其室温干滑动磨损机制为软磨料磨损和氧化磨损;对于以Ni3Ti为初生相的合金,其室温干滑动磨损机制在中低负荷下为氧化磨损和显微切削,在高负荷下则是Ni3Ti的显微切削;以NiTi为初生相的NiTi/Ni3Ti金属间化合物合金具有更好的抗室温摩擦磨损性能。
The wear-resistant NiTi/Ni3Ti intermetallic alloys were designed and fabricated by the laser melting deposition process. The as-solidified microstructures of the NiTi/Ni3 Ti intermetallic alloys were characterized by X- ray diffraction(XRD), optical microscope(OM), scanning electron microscope(SEM) and energy dispersive spectrometer(EDS). The wear resistance of the alloys was evaluated under room-temperature dry sliding wear test condition coupling with hardened bearing steel GCr15. The results indicate that the room temperature dry-sliding wear mechanism of the NiTi/Ni3Ti intermetallic alloy with NiTi dendrite as the primary phase is soft abrasion and oxidative wear, while that of the NiTi/Ni3 Ti intermetallic alloy with Ni3 Ti as the primary phase is oxidative wear and micro-cutting under low/medium normal load, and micro-cutting is under high normal load; the NiTi/Ni3Ti intermetallic alloy with NiTi dendrite as the primary phase has better wear resistance under dry sliding wear test conditions than that with Ni3Ti as the primary phase.