激光原位合成TiB-TiC颗粒增强钛基复合材料的组织与其耐磨性能

采用激光沉积制造技术原位合成以TiB-TiC为增强相的钛基复合材料。借助XRD、SEM、EDS以及硬度测试和室温耐磨实验,研究钛基复合材料的组织及其耐磨性能。结果表明:制备样品中的强化相为TiC和TiB,其中TiC呈近似等轴状,TiB呈晶须状或棱柱状;随着增强相含量的增加,钛基复合材料硬度增加,但摩擦系数变化不大,磨损失重先减小后增大,说明钛基复合材料的耐磨性能不仅仅与硬度有关;与基材相比,B元素和C元素为1.2%和0.84%(质量分数)的钛基复合材料具有较好的耐磨性能,其磨损失重仅为基材的53%;钛基复合材料的磨损机制为磨粒磨损和极少量氧化磨损的共同作用。

Microstructure and Wear-resistant Properties of the in situ TiB-TiC Reinforced Titanium Matrix Composites by Laser Deposition Manufacturing

The TiB-TiC Reinforced Titanium matrix composites (TMCs) were manufactured by Laser Deposition Manufacturing (LDM) technique with the ball milled TA15+B₄C powders with different compositions of B and C elements. The microstructure and wear-resistant properties of the prepared TMCs were studied by XRD, SEM, EDS, hardness test and wear resistance test. The obtained results revealed that in the prepared TMCs, there were two types of the reinforcement, namely the TiC reinforcement with the near-equiaxed shape and the TiB reinforcement with the whisker or prismatic shape. With the increase in the reinforcement content, the hardness of TMCs improved, the friction coefficient might be unchangable and the wear mass loss increased first and then decreased. Compared with the substrate, the TMC containing 1.2 wt% boron and 0.84 wt % carbon showed better wear-resistant properties. The wear mechanism of the prepared TMCs involved the abrasive wear and a small amount of oxidation wear.