多孔NiTi形状记忆合金的制备及性能  

Property and Preparation of Porous NiTi Shape Memory Alloy

作　　者：马旭梁[1,2] 李莉[1] 朱成武 王香 郑玉峰 

机构地区：[1]哈尔滨工程大学生物医学材料与工程研究中心,哈尔滨150001 [2]哈尔滨理工大学材料科学与工程学院,哈尔滨150080

出　　处：《材料工程》2011年第3期6-10,59,共6页Journal of Materials Engineering

摘　　要：采用球磨后的NiTi合金粉末为原料,添加尿素作为造孔剂,利用粉末烧结法制备多孔NiTi形状记忆合金。研究烧结温度、保温时间和预成型压力等条件对制备的多孔NiTi合金组织结构和力学性能的影响。结果表明:相对于传统的Ni粉和Ti粉近等原子比混合烧结方法,此方法制备的多孔NiTi合金的相组成更加纯净。且随烧结温度升高,多孔NiTi合金的孔隙尺寸逐渐增大,孔隙分布趋于均匀,抗压强度增加。随保温时间的延长,孔径减小,液化现象明显,强度增加。在预成型压力的变化过程中存在最优值,选取最优值可获得组织特性较好的多孔合金制品。并最终确定在添加70%造孔剂时,预成型压力为150MPa,1050℃保温5h条件下可制备出性能优异的多孔NiTi合金。Porous NiTi shape memory alloy（NiTi SMA） was fabricated by powder metallurgy technology using ball milled NiTi powder as raw material and adding urea as a pore-forming agent.The effects of sintering temperature,holding time and pre-forming pressure on the microstructure and mechanical properties of the prepared porous NiTi SMA was studied.The results show that： compared with conventional sintering of mixture powder of Ni and Ti,the phase constituents of the porous NiTi alloy made by this method is more pure.And with the increasing of the sintering temperature,the pore size of porous NiTi alloy gradually increases,the pore distribution tends to be uniform,and compression strength is increased.With the extended holding time,pore size is decreased,the phenomenon of liquefaction is obvious and the strength is increased.There is an optimal value of the pre-forming pressure,and the porous NiTi alloy products can be well produced by the optimal pre-forming pressure.And the process of adding 70% pore-forming agent,pre-forming under the pressure of 150MPa,and holding at 1050℃ for 5h were ultimately determined,the porous NiTi alloy fabricated under the conditions has excellent property.

关 键 词：多孔NITI形状记忆合金 粉末冶金 组织结构 力学性能 

分 类 号：TG139[一般工业技术—材料科学与工程]