钛合金表面激光熔覆（Ti＋Al/Ni）/（Cr2O3＋CeO2）复合涂层组织写耐磨性能

为改进钛合金(Ti6A14V)的耐磨性能,应用脉冲Nd:YAG激光器进行了钛合金表面熔覆(Ti Al/Ni) (Cr_2O_3 CeO_2)复合涂层实验,分析了熔覆层微观组织,测试了熔覆层显微硬度及其在大气环境室温下的摩擦磨损性能。结果表明,熔覆层组织是在细小树枝晶和共晶基体上散布着未熔Cr_2O_3颗粒和白亮球状液析Cr_2O_3,及生成的硬化TiAl陶瓷颗粒增强相。显微硬度明显提高,最高可达1150HV,平均是基材的3～4倍。熔覆层和基材实现良好冶金结合,白亮熔合区宽度为10～20μm。激光熔覆层干滑动摩损的摩擦系数在0．2～0．3之间,磨损率比Ti6A14V标样降低约4～5倍。

Microstructure and Wear-Resisting Property of (Ti AI/Ni)/(Cr_2O_3 CeO_2) Laser Cladding on Titanium Alloy

To improve the wear-resisting property of titanium alloy (Ti6Al4V), an experiment of laser cladding (Ti+Al/Ni)/(Cr2O3+CeO2) on titanium alloy by pulsed Nd:YAG laser had been carried out. The microstructure of the clad layer was investigated, and the microhardness was measured. The friction and wear properties of the clad layer were examined in atmosphere. It was found that the microstructures of the clad layer were dispersive undissolved Cr2O3 particles and orbed liquid-precipitated Cr2O3 distributed in the matrixes consisting of fir-tree crystals and eutectics. And a small amount of TiAl ceramic hardening particles was existed. The hardness of the clad zone increased obviously, the maximum was 1150HV, 3～4 times of the substrate. A white narrow metallurgical bonding zone was formatted at interface between the cladding and the substrate, about 10～20 μm. The friction coefficients of the clad layer in dry sliding wear were ranged from 0.2 to 0.3. And the rate of wearing was 4～5 times lower than that of Ti6Al4V alloy guide samples.