激光熔覆层中非晶组织对摩擦学的影响

使用 5k W CO2 激光器对铝合金表面的 Ni- Cr- Al涂层进行熔覆处理 .分析发现 ,熔覆层中存在大量的非晶组织 .利用差热分析 DTA 方法半定量地确定非晶组织的含量 ,并对不同非晶含量的试样与灰铸铁进行摩擦磨损试验 .结果表明 ,激光熔覆试样的磨损量非常小 ,非晶含量越高 ,磨损量越小 .激光熔覆试样的摩擦系数在油润滑条件下相差不大 ,灰铸铁的摩擦系数在磨程 2 km后趋于稳定 ,且均小于 0 .1

Effect of Amorphous Structure in the Laser Clad Zone on Tribological Characteristics

Using a 5 kW CO 2 laser, a Ni Cr Al plasma coating on Al Si alloy surface was remelted as a cladding layer. The microstructural analysis showed that there are some amorphous structures in the clad zone that co exist with crystalline Ni 3Al. A semi quantitative method using DTA was used to determine the content of amorphous structure in the zone. Wear tests of laser clad samples using different amorphous contents paired with grey cast iron were carried out under oil lubricated condition. Experimental results show that the wear amount of laser clad samples was quite small. The higher the content of amorphous structure, the smaller the wear amount. All friction coefficients of the clad samples versus grey iron pairs tended to stability and they were less than 0.1 after the sliding distance exceeded 2 km.