WC量对发动机用Ti600表面激光熔覆Ni60A涂层性能的影响

在Ni60A粉末内加入10%、20%与30%不同质量分数WC颗粒,利用激光熔覆方法在发动机用Ti600基底表面形成Ni60A/WC涂层,通过实验测试手段分析WC量对涂层组织及性能的影响。研究结果表明:形成了具有同样成分的Ni60A涂层,析出了等轴晶、长条形、环状组织。在Ni60A涂层内加入20%的WC之后,获得了更致密的Ni60A涂层,表现为明显的网篮型组织形态,此时形成了许多细小的TiC晶粒,并且TiB比例大幅提高。加入WC情况下,形成的Ni60A涂层硬度明显增加。加入30%Ni60A/WC后,获得了最大硬度的Ni60A涂层,与基底相比提高了近2倍。由此表明,Ni60A涂层相对于基底组织发生了硬度的大幅提高。加入WC后,摩擦系数减小到0.6以内,磨损量减小到1.0 mg以内,表明Ni60A/WC可以发挥良好减摩效果。在试样表面形成了许多鱼鳞外形的碎屑,加入Ni60A/WC后可以使Ni60A涂层获得更强的耐磨能力。

Influence of WC Mass Fraction on Tribological Properties of Ti600 Alloy Modified with Laser Cladded WC-Doped Ni60A Coating

The surfaces of Ti600 alloy,an aviation engine blade material,were modified with laser cladded Ni60 A/WC coating.The influence of the WC mass fraction on the microstructures and tribological behavior of the WC-added Ni60 A coatings was investigated with X-ray diffraction,scanning electron microscopy and mechanical probes.The results show that the WC-addition makes the difference.For example,as the WC mass fraction increased from 10% to 30%(wt),the compactness,density and wear-resistance of the Ni60 A/WC coatings,comprising equiaxed and dendric texture surrounded by an increasing density of TiC nano-grains,increased to varying degrees,and the friction coefficient significantly decreased to below 0.6.Added at WC 30%,the hardness of the coatings had a decreasing hardness depth profile,with the Max surface-hardness 2 times higher than that of Ti600 alloy.Abrasive wear was found to explain the wear mechanism.