铁基合金激光熔覆层的摩擦学特性

Tribological Behavior of Fe-Based Alloy Coating Formed by Laser Cladding

为评估激光熔覆技术修复塑料模具的磨损性能,采用铁基合金粉末在40Cr钢基体表面进行激光熔覆。激光熔覆层为上试样,GCr15钢球为下试样,利用HT-500磨损试验机进行摩擦磨损试验,研究在干摩擦、润滑条件下,激光熔覆层及其配副的摩擦学特性。利用表面形貌仪测量磨痕的深度和宽度,理论计算磨损率。研究结果表明,在干摩擦条件下,随载荷的增加,激光熔覆层及其配副的摩擦系数先降低后增加,当载荷为300 g时摩擦系数最小;随载荷的继续增加,摩擦系数逐渐增大。在相同载荷与润滑条件下,激光熔覆层及其配副的摩擦系数、磨损率、磨痕宽度均小于干摩擦条件下的值;随着磨损时间的增加,摩擦系数在磨损后期略有上升,磨损深度、磨损体积、磨损率逐渐增大。

In order to investigate the tribological performance of laser clad coating on die steel, laser cladding techniques were adopted with Fe-based alloy powders. The tests were carried out by using laser clad layers as upper samples and GCr15 steel as low samples with HT-500 wear tester. The morphologies of wear scars were observed with optical microscopy, and the width and the depth of the wear samples were measured. In the meantime, the wear rate was calculated theoretically. Under dry sliding condition, As the tests shown, friction coefficient decreases with the load increasement gradually, and then increases. And the wear performance of 300 g load is better than that of 500 g load under dry sliding condition. Under lubricant condition, with the increasement of load, the friction coefficient decreases gradually. And the friction coefficient, wear rate and wear width under lubricant are smaller than those under dry friction with the same load.