Effects of different bionic units coupling on the sliding wear of gray cast iron

To enhance the sliding wear resistance of gray cast iron under starved lubrication conditions, two kinds of bionic units were generated by using a pulsed Nd: YAG laser and a drill on the surface of the specimens. The microstructure and microhardness of the bionic strip unit were examined. Comparing the wear resistance of five groups of specimens (an untreated specimen; a specimen with a surface that was completely melted by the laser; a specimen containing only bionic pit unit; a specimen containing only bionic strip unit and a specimen coupling two kinds of bionic units), the results indicate that the wear resistance of the bionic unit coupling specimen is better than that of the others. The result of a stress analysis of the specimen surface shows that the bionic strip unit plays a supporting role and can reduce the stress concentration on the edge of the bionic pit unit. On the other hand, the bionic pit unit can supply lubricating oil to the wear gap, change the moving model of abrasive grains and improve the lubrication performance. The two kinds of units can protect and promote each other under starved lubrication conditions, improve the resistance to sliding wear.