Process mechanism in laser peen texturing artificial joint material

Abstract

Friction and wear of artificial joints seriously restrict the service life of them. Surface texturing has been recognized as an effective means to reduce friction coefficient and improve wear resistance of artificial joints. In this study, a new and promising technology named laser peen texturing (LPT) is proposed to fabricate dimple textures on artificial joints. Process applicability of LPT on artificial joint material 316 L stainless steel is studied by experiments. Experimental results show that LPT is capable of fabricating dimple arrays on 316 L stainless steel and has good controllability and repeatability. Fundamental process mechanism of LPT is explored by numerical simulation. A 2D axisymmetric and semi-infinite finite element analysis (FEA) model has been developed and validated to predict the stress distribution and deformation process of the biomedical metal. The simulated dimple profiles are well consistent with the measured ones. Stress analysis shows obvious residual compressive stress after LPT. The maximum residual compressive stress and the thickness of the residual compressive stress zone are sensitive to LPT processing parameters. The local dynamic elasto-plastic deformation process of the material is discussed based on the deformation analysis at different time.