原位自生(TiB+La_(2)O_(3))/TC21钛基复合材料组织与性能分析

Analysis of Microstructure and Properties of In-situ (TiB+La_(2)O_(3)) /TC21 Titanium Matrix Composites

以TC21钛合金粉和LaB_(6)粉为原料,采用热压烧结制备原位自生(TiB+La_(2)O_(3))/TC21钛基复合材料以及TC21钛合金,利用光学显微镜(OM)、扫描电镜(SEM)、X射线衍射(XRD)仪、维氏硬度仪、电子万能试验机等对比分析了复合材料和钛合金退火后的组织和力学性能。结果表明:复合材料和钛合金的组织均为网篮组织;LaB_(6)和Ti发生原位反应生成TiB及La_(2)O_(3)增强体,TiB呈短纤维状,La_(2)O_(3)有颗粒状、板条状、短纤维状多种形貌,且随LaB_(6)添加量增加La_(2)O_(3)颗粒长大及聚集;随着LaB_(6)添加量增加,复合材料维氏硬度和抗压强度升高而塑性下降。

Using TC21 titanium alloy powder and LaB_(6) powder as raw materials,in-situ(TiB+La_(2)O_(3))/TC21 titanium matrix composites and TC21 titanium alloy were prepared with hot pressing sintering.The microstructure and mechanical properties of the composites and titanium alloy after annealing were studied by optical microscope(OM),scanning electron microscope(SEM),X-ray diffraction(XRD),Vickers hardness tester and electronic universal testing machine.The results show that the microstructure of the composite and titanium alloy is basket structure.TiB and L_(a2)O_(3) reinforcement are formed by in-situ reaction between LaB_(6) and Ti.TiB is in short fiber dimension.La_(2)O_(3) has various morphologies of particle,strip and short fiber,and La_(2)O_(3) particles grow and aggregate with the increase of LaB_(6) addition.With the increase of LaB_(6) addition,the Vickers hardness and compressive strength of the composites increased and the plasticity decreased.