Fabrication, microstructure and mechanical properties of W-NiTi composites
Fabrication, microstructure and mechanical properties of W-NiTi composites
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W-NiTi复合材料的制备、显微组织和力学性能
DOI：
10.1016/j.jallcom.2016.11.032
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发表时间：
2017-02-25
影响因子：
6.2
通讯作者：
Cui, Lishan
中科院分区：
文献类型：
--
作者：
Shao, Yang;Guo, Fangmin;Cui, Lishan
采用熔渗-热压工艺制备了含88wt%钨粉和12wt%近等原子NiTi合金的新型两相钨基复合材料。通过对W-Ni 50 Ti 50、W-Ni 44 Ti 56、W-Ni 42 Ti 58和W-Ni 42 Ti 53 Nb 5复合材料的对比，研究了NiTi母合金中Ti/Ni比的变化以及Nb元素的加入对W-NiTi复合材料的显微组织、马氏体相变和力学性能的影响。结果表明，W-Ni 50 Ti 50和W-Ni 44 Ti 56复合材料中形成了脆性的Ni 3 Ti，W-Ni 42 Ti 58复合材料中形成了脆性的Ti 2Ni，而W-Ni 42 Ti 53 Nb 5复合材料中没有形成脆性的金属间化合物。W-Ni_（42）Ti_（53）Nb_5复合材料的马氏体相变最剧烈，相变焓最大。W-Ni 42 Ti 53 Nb 5复合材料在压缩下表现出双屈服现象，其极限压缩强度为3820 MPa，变形量为50.4%。原位同步辐射高能X射线衍射测量显示，第一屈服是由于马氏体的NiTi基体的重新取向和第二是由于大规模的塑性变形的重新取向的马氏体的开始，也归因于微观内部断裂的W颗粒。(C)2016爱思唯尔B. V.保留所有权利。
New two-phase tungsten-based composites containing 88 wt% tungsten powders and 12 wt% nearly equiatomic NiTi alloy deforming by martensite variant detwinning were fabricated by infiltration and hot pressing in this study. The change of Ti/Ni ratio in NiTi mater alloy and the effect of addition of Nb element on the microstructure, martensitic transformation and mechanical properties of W-NiTi composites were investigated by comparison of W-Ni50Ti50, W-Ni44Ti56, W-Ni42Ti58 and W-Ni42Ti53Nb5 composites. The results showed that brittle Ni3Ti formed in the W-Ni50Ti50 and W-Ni44Ti56 composites and brittle Ti2Ni formed in the W-Ni42Ti58 composites while no brittle intermetallics formed in the W-Ni42Ti53Nb5 composite. The W-Ni42Ti53Nb5 composite exhibited the sharpest martensitic transformation with the largest transformation enthalpy among the four different composites. The W-Ni42Ti53Nb5 composite exhibited a double-yielding phenomenon under compression with an ultimate compressive strength of 3820 MPa and a deformation of 50.4%. In-situ synchrotron high-energy Xray diffraction measurements revealed the first yielding was caused by the martensite reorientation of the NiTi matrix and the second was due to the commencement of massive plastic deformation of the reoriented martensite and is also attributed to the microscopic internal fracturing of the W particles. (C) 2016 Elsevier B.V. All rights reserved.