钛镍多孔材料的制备及其显微组织与形状记忆性能

Preparation of Porous NiTi Alloy and Its Microstructure and Shape Memory Properties

采用粉末烧结法制备了高孔隙率的Ti-50.8 at%Ni形状记忆合金(SMA),并对其显微组织和形状记忆性能进行了研究。结果表明,用该种方法制备的多孔合金样品具有孔隙分布均匀以及开孔率高的特点,其平均孔径在200μm左右。合金组织主要由奥氏体NiTi相(B2)和单斜马氏体NiTi相(B19’)组成。循环加载-卸载实验结果表明,该多孔材料能表现出一定的形状记忆效应,而且形状记忆效应随孔隙率的增加而降低。

Porous Ti-50.8 at%Ni shape memory alloys （SMA） with high porosity were prepared by the powder metallurgical technique and the microstructure and shape memory behavior of the porous alloys were investigated. The results indicate that the porous alloys prepared by this method exhibit a homogenous pore-space structure with a high open-cell ratio, and the average pore size is about 200 μm. The microstructure is mainly composed of Austenitic NiTi phase （B2） and monoclinic Martensite NiTi （B19＇）. The cyclic load-unload recovery curves reveal that the porous alloy can exhibit certain shape-memory effect, which decreases with the increase of the porosity