Characterization of high-strength Ti-Ni shape memory alloys prepared by hot pressed sintering
Characterization of high-strength Ti-Ni shape memory alloys prepared by hot pressed sintering
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热压烧结高强度Ti-Ni形状记忆合金的表征
DOI：
10.1016/j.jallcom.2020.157159
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发表时间：
2021
影响因子：
6.2
通讯作者：
Cai Wei
中科院分区：
文献类型：
--
作者：
Yi Xiaoyang;Wang Haizhan;Sun Kuishan;Gao Weihong;Sun Bin;Shen Guijuan;Meng Xianglong;Gao Zhiyong;Cai Wei
采用Ti-Ni合金粉末热压烧结方法制备高强度Ti-Ni形状记忆合金。由于较高的烧结温度和辅助80MPa的外部压力，可以获得更高密度的Ti-Ni合金。在适当的烧结温度下烧结的Ti-Ni合金的特征是Ti2Ni相沿原始合金粉末表面分布形成的网络结构。由于化学成分均匀，无论烧结温度如何，在固结的 Ti-Ni 合金中仅观察到一级 B2⇌B19' 马氏体转变。随着烧结温度的升高，马氏体转变温度略有变化，这在很大程度上与Ti2Ni相的数量和分布有关。随着烧结温度的升高，现有Ti-Ni合金的机械性能得到提高。此外，1000℃制备的Ti-Ni合金具有优异的应变恢复特性，在10%预应变条件下可恢复应变为8.13%，这归因于Ti2Ni相具有较高的屈服应力和较弱的马氏体界面运动阻碍作用。
High strength Ti–Ni shape memory alloy had been manufactured by hot-pressed sintering of Ti–Ni alloy powders. Due to the higher temperature sintering and assisted with the external pressure of 80 MPa, the higher density of Ti–Ni alloys can be obtained. The Ti–Ni alloy sintered at the appropriate sintering temperature was characterized by the network structure formed by the Ti2Ni phase distributing along the surface of original alloy powders. Merely one-stage B2⇌B19′ martensitic transformation was observed in the consolidated Ti–Ni alloy due to the homogeneous chemical composition, irrespective of the sintering temperature. The martensitic transformation temperature slightly changed, which was largely related to the number and distribution of Ti2Ni phase, as the sintering temperature increased. The mechanical properties of present Ti–Ni alloy were enhanced with the increased sintering temperature. Moreover, the outstanding strain recovery characteristics with the recoverable strain of 8.13% at the pre-strain of 10% condition can be achieved in Ti–Ni alloy prepared at the temperature of 1000 °C, which was attributed to the higher yield stress and weaker hamper effect of Ti2Ni phase on the movement of martensitic interface.