Tribological properties of MAO coating deposited on aluminum base bearing alloy with different texture shapes

In order to expand the wide application of aluminum base bearing alloys. Triangular, square, and circular textures were created on ZL105A aluminum alloy surfaces using a laser, each with the same depth and area occupancy rate. Subsequently, a micro-arc oxidation composite treatment was applied. Through the use of energy dispersive spectrometry, electron microscopy, optical profilometer scanning, and X-ray diffraction, the shape, structure, and composition of the coating were examined. The specimens' tribological characteristics were assessed using a pin-disk contact rotary friction and wear tester in conditions where oil lubrication was applied. The findings indicate that the MAO coating consists primarily of Al and gamma-Al2O3 phases. Additionally, the presence of the "sharp corner effect" impacts the formation of the MAO coating, on the textured substrate surface, Al is easier to combine with oxygen and transform into alumina, and the "sharp corner effect" will cause the coating to thicken at the edge of texture. In terms of tribological characteristics, the triangular texture exhibits superior friction reduction and anti-wear performance compared to other textures in the absence of MAO coating. In comparison, the MAO sample coefficient of friction is enhanced compared to the substrate due to the raised roughness and hardness of the coating after the surface texture composite micro-arc oxidation. Meanwhile, thetexture of the composite-modified sample serves as a storage for wear debris and lubricating oil, providing effective protection against coating failure and significantly reducing wear.