Ti_2SnC原位自生TiC_(0.5)增强Cu基复合材料的制备及压缩特性

本文以Ti_2SnC陶瓷为先驱体,利用其高温下与Cu的反应原位自生TiC_(0.5)颗粒增强Cu基复合材料并研究了其压缩特性。通过差热分析、X射线衍射和扫描电子显微镜等手段分析了Ti_2SnC与Cu的反应行为,并探讨了制备工艺对复合材料的物相组成、增强相形貌及材料特性的影响。结果表明,Ti_2SnC与Cu在900°C就开始发生反应,Ti_2SnC中的部分Sn原子逃逸扩散到Cu基体内,留下TiC_(0.5)作为增强相颗粒;随着温度的升高,反应程度加剧;当温度达到1150°C时,Ti_2SnC全部分解,形成亚微米TiC_(0.5)增强Cu(Sn)复合材料。TiC_(0.5)颗粒随保温时间增加而更加均匀地分布在基体内。对于初始Ti_2SnC体积含量为30%的TiC_(0.5)/Cu(Sn)复合材料,保温时间从0 h增加至2 h,其抗压强度和压缩变形率分别从1109 MPa±11 MPa和24.4%±0.6%增加到1260 MPa±22 MPa和28.9%±1.1%。

Fabrication and Compression Properties of TiC0.5/Cu(Sn) Composites in-situ Synthesized from Cu and Ti2SnC Powders

TiC0.5 particle reinforced Cu matrix composite was in-situ fabricated from Ti2SnC and Cu powders. The reaction behavior between Ti2SnC and Cu was studied by DSC, XRD and SEM. The phases, microstructures and the compression properties of the prepared TiC0.5/Cu(Sn) composites were explored. Meanwhile, the relationships among the fabrication processes, the microstructures and the compression properties of the composites were studied. The results showed that, the initial reaction temperature between Ti2SnC and Cu is about 900°C. The reaction process shows that parts of Sn atoms in the Ti2SnC would diffuse into Cu matrix, leaving TiC0.5 particles as reinforcements. The diffusion of Sn atoms and Cu atoms is intensified, and some TiC0.5 microcrystal begins to form within the Ti2SnC particles as the sintering temperature increases. The distribution of TiC0.5 particles in the matrix would become more and more homogeneous as the holding time prolonged during sintering. Respectively, the compression strength and compression fracture strain of TiC0.5/Cu(Sn) composites were improved from 1109 MPa ± 11 MPa and 24.4% ± 0.6% to 1260 MPa ± 22 MPa and 28.9% ± 1.1 %, respectively, as the holding time increased from 0 h to 2 h.