Ti-Al-Cr-Nb-V合金激光表面原位TiC颗粒增强涂层及耐磨性研究

分别以高纯石墨粉C和C Nb混合粉末为原料，对Ti-46Al-2Cr-1．5Nb-1V合金进行了激光表面合金化处理，对激光改性层的显微组织以及成分进行了观察与分析，并对该合金原始组织及经C或C Nb激光表面改性层的室温耐磨性能进行了对比分析研究。研究结果表明，C和C Nb激光表面合金化处理后，在合金表面均“原位”形成了TiC颗粒，Nb以固溶原子形式存在于表面改性层中，TiC颗粒的大小，形态及分布强烈取决于激光工艺参数；经C或C Nb激光表面合金化处理后，TiAl合金的室温滑动磨损耐磨性能均有不同程度的提高，其中经C Nb的激光表面合金化后的试样表现出最佳的抗室温滑动磨损性能。

Microstructure Characteristics and Wear Resistance of TiC Particle Reinforced Coatings by Laser Surface Alloying in a Ti-Al-Cr-Nb-V Alloy

Laser surface alloying with C and C+Nb was used to modify the surface properties of Ti-46Al-2Cr-1.5Nb-1V alloy. The microstructure of the laser alloyed surface layer was studied as a function of laser processing parameters. The wear resistance of the original alloy and the samples laser surface alloyed with C and C+ Nb at room temperature were investigated. The results indicate that,the particles of TiC are in-situ produced in the laser treated surface layer for the samples laser surface alloyed with C and C+Nb. Nb exists in the alloy matrix as the solute atom. The size, shape and distribution of TiC are strongly dependent on the laser processing parameters. By laser surface alloying with C or C+Nb powders, wear resistance of the Ti-Al-Cr-Nb-V alloy at room temperature improved in comparison with the original alloy and the sample alloyed with C+Nb exhibits the best wear resistance.