304不锈钢表面离散圆形凹坑液相辅助激光制备及摩擦性能

为改善304不锈钢耐磨性及润湿性，在空气与液相2种介质下使用激光加工技术在304不锈钢表面制备离散型圆形凹坑织构。借助白光干涉仪、扫描电子显微镜及能谱、接触角测量仪对织构试样表面形貌、元素含量及润湿性进行了表征，并通过摩擦磨损试验考察了织构试样在干摩擦和油润滑下的摩擦学性能。结果表明：空气介质下激光加工增强了试样表面疏水性能，接触角为123.3°；液相辅助激光加工增强了试样表面润湿性，接触角为29.3°；液相辅助激光加工表面的微凹坑分布更加均匀，无明显的氧化及熔融物重铸现象，这是因为液相在激光加工时对试样起到了冷却及保护作用；液相辅助激光加工表面织构在2种摩擦工况下的摩擦因数均最小，且磨损有一定改善。液相辅助激光制备的织构表面较为均匀、无较大的微凸峰，且具有较好的润湿性能，有利于润滑油的存储及铺展，进而改善了界面摩擦行为。

Liquid-phase Assisted Laser Preparation and Friction Properties of Discrete Circular Pits on 304 Stainless Steel Surface

In order to improve the wear resistance and wettability of 304 stainless steel,the discrete circular pit texture was prepared by laser processing technology in air and liquid media.With the help of contour white light interferometer,scanning electron microscope,energy spectrum and contact angle measuring instrument,the surface morphology,element content and wettability of textured samples were characterized,and the tribological properties of textured samples under dry friction and oil lubrication were investigated through friction and wear tests.The results show that the hydrophobicity of the textured samples by laser processing in air medium is enhanced,and the contact angle is 123.3°.The wettability of the textured samples by liquid phase assisted laser processing is enhanced,and the contact angle is 29.3°.The distribution of micro pits on the liquid phase assisted laser processing surface is more uniform,and there is no obvious oxidation and molten recasting phenomenon.This is because the liquid phase plays a role in cooling and protecting the sample during laser processing.The friction coefficient of liquid assisted laser processing surface texture is the smallest under two friction conditions,and the wear is also improved.The textured surface prepared by liquid assisted laser processing is relatively uniform,without large micro bumps,and has good wetting performance,which is conducive to the storage and spreading of lubricating oil,thereby improving the interface friction behavior.