Numerical optimization of gourd-shaped surface texture and experiment of tribological performance

A numerical optimization approach based on the finite element (FE) simulation was used to design the optimum irregular gourd-shaped pattern parameters for generating the highest hydrodynamic pressure. Then the optimum parameters of the gourd-shaped surface texture were determined and the textures were processed on the stainless steel surface by the laser technology.The tribological performance of gourd-shaped surface texture was analyzed using the type of UMT2 tester, and compared with that of the regular circle surface texture and none-texture surface by considering the effect of sliding speeds and applied loads on the tribological performance. The results show that the compound factor n, the diameter ratio Dr and the texture depth Hd are more significant parameters and the optimum values are 0.618, 2.0 and 4 μm, respectively. In addition, irregular gourd-shaped surface texture with optimum parameters is the most effective in the friction reduction among the patterns investigated under different speeds and applied loads in this work. Moreover, better coordination and combination effect can be obtained by gourd-shaped surface texture. The main reason responsible for the results is the irregular symmetric nature of the gourd-shaped texture along the direction of lubricants flowing which can generate the higher fluid dynamic pressure.