A procedure for producing equiatomic high-density NiTi shape memory alloy (SMA) from pre-alloyed NiTi powders and the mixture of elemental Ni and Ti powders by vacuum hot pressing sintering was described, respectively. Phase composition, microstructure and mechanical properties of such a procedure were discussed by XRD, metallurgical microscope, SEM and electronic universal testing machine. The results show that at 1 100 *C and 25 MPa, nearly full density and homogeneous TiNi microstructures are produced. The relative density values of NiTi from pre-alloyed powders and mixture powders are 99.64% and 98.03%, respectively. Specimens, produced from pre-alloyed powders, are more homogeneous and have better mechanical properties.%采用真空热压烧结技术,分别以NiTi预合金粉末和Ni,Ti纯元素混合粉末制备等摩尔比的NiTi形状记忆合金(SMA).利用X线衍射仪、金相显微镜、扫描电子显微镜及电子万能试验机对其物相组成,显微结构及力学性能进行分析.研究结果表明:在1100℃和25MPa真空热压条件下,可制备出近全致密且组织及性能优良的镍钛合金,其中预合金粉末和元素混合粉末所制备样品的相对密度分别可达到99.64％和98.03％,并且预合金粉末样品比元素混合粉末样品具有更均一的组织和更好的力学性能.
展开▼
