Effect of MoO_3 addition on the microstructure and mechanical properties of Ti_2A1C prepared by reactive hot pressing
Effect of MoO_3 addition on the microstructure and mechanical properties of Ti_2A1C prepared by reactive hot pressing
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DOI：
10.1557/jmr.2013.215
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发表时间：
2013-08
影响因子：
2.7
通讯作者：
Jianfeng Zhu;R. Pan;Fen Wang
中科院分区：
文献类型：
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作者：
Jianfeng Zhu;R. Pan;Fen Wang
以Ti、Al、TiC和MoO_3为原料，在1350 °C下反应热压制备了高纯度、致密的（Ti，Mo）_2AlC/Al_2O_3原位复合材料。研究了MoO_3含量对合金相组成、显微组织和力学性能的影响。在Ti-Al-TiC体系中引入Al-MoO_3置换反应，得到了亚微米级的晶粒尺寸和均匀分布的基体相（Ti，Mo）_2AlC和第二相Al_2O_3。随着Al_2O_3含量的增加，基体晶粒明显细化。与未添加MoO_3的试样相比，添加13.81wt%MoO_3（相当于10wt%Al_2O_3生成量）的试样的硬度、抗弯强度和断裂韧性分别提高了25%、69%和146%。研究了（Ti，Mo）_2AlC/Al_2O_3复合材料的强韧化机理。
Fully dense (Ti,Mo)_2AlC/Al_2O_3 in situ composites with high purity were successfully synthesized at 1350 °C by reactive hot pressing of the Ti, Al, TiC, and MoO_3 powder mixtures. The effect of MoO_3 content on the phase composition, microstructure, and mechanical properties was investigated in detail. The introduction of the Al–MoO_3 displacement reaction into the Ti–Al–TiC system resulted in a submicron grain size and a homogeneously distributed matrix phase of (Ti,Mo)_2AlC with a secondary Al_2O_3 phase. The matrix grain size was significantly refined with increasing the Al_2O_3 content. Compared with the sample without MoO_3 addition, the addition of 13.81 wt% MoO_3 (corresponding to 10 wt% Al_2O_3 formation) evidently enhanced the hardness, flexural strength, and fracture toughness by 25%, 69%, and 146%, respectively. The strengthening and toughening mechanisms for the (Ti,Mo)_2AlC/Al_2O_3 composites were also investigated.