(Ti,Al)C涂层的液相脉冲放电制备及其滑动磨损性能

Preparation of Titanium/Aluminum Carbide Alloy Coating by Pulse Discharge in Liquid Phase and Evaluation of Its Sliding Friction and Wear Behavior

为了制备耐磨性和抗氧化性优良、结合力高的多元合金涂层,利用普通电火花机床通过液相脉冲放电法在调制态45钢基体上制备了(Ti,Al)C涂层,采用X射线衍射仪(XRD)分析了涂层的相组成,利用带有能谱分析仪的扫描电镜观察了涂层的界面组织、分析了涂层的元素成分,采用显微硬度计测试了涂层的硬度,采用摩擦磨损试验机考察了涂层的滑动磨损特性。结果表明:液相脉冲放电法制备的涂层厚约30μm,主要物相为(Ti,Al)C,从涂层到基体,试样硬度呈梯度递减,涂层表面硬度高达2 100 HV以上;与淬火低温回火45钢配副时,摩擦系数较低且稳定;摩擦磨损试验载荷为100～200 N时,涂层表面出现轻微塑性变形,磨损机制为塑性流变;载荷为300～400 N时,涂层磨损面出现浅而细的平行状犁沟,磨损机制为轻微磨粒磨损。

(Ti,Al)C alloy coating was prepared on the surface of quenched and tempered 45 steel by pulse discharge in liquid.The phase ingredient,microstructure and elemental composition of asprepared(Ti,Al)C coating were analyzed by means of Xray diffraction,scanning electron microscopy,and energy dispersive spectrometry.Moreover,a microhardness meter was performed to determine the microhardness of asprepared(Ti,Al)C coating,and a friction and wear tester was adopted to evaluate its sliding friction and wear behavior.Results showed that asprepared(Ti,Al)C coating had a thickness of about 30 μm and mainly consisted of(Ti,Al)C phases.Besides,the microhardness tended to decline in a gradient manner from the coating surface to the steel substrate,and the microhardness of the coating surface was above 2 100 HV.When asprepared(Ti,Al)C coating was coupled with quenched and tempered 45 steel,a low and stable friction coefficient was recorded.When the pressure of 100~200 N was applied,the worn surface of the coating showed signs of mild plastic deformation.However,when the pressure of 300~400 N was applied,the worn surface showed shallow and narrow parallel scuffs,which indicated it was dominated by slight abrasive wear in this case.