Investigation of the effect of laser surface texturing parameters on the tribological performances of ultra-high molecular weight polyethylene surfaces

Surface texturing methods are applied to materials in many industries; It is used to provide different properties such as lubricity, hydrophobicity, friction, and wear-reducing effects. Within the scope of this study, it is aimed to reduce the negative effects such as surface damage and limited life caused by the friction in the hip implant connections and therefore the wear effects. Friction and wear values were calculated by tribological tests by making patterns with nanosecond laser and femtosecond lasers on the ultra-high molecular weight polyethylene surfaces, which are among the co-working parts in the hip prosthesis. Within the scope of the tribological experiment, 3 different materials were used and these materials are cross-linked polyethylene GUR 1020 XL (UHMWPE), cross-linked vitamin E added polyethylene GUR 1020 EXL (UHMWPE EXL), and standard polyethylene (UHMWPE). When the friction coefficients of the materials were examined, it was determined that UHMWPE EXL had the lowest friction coefficient and the most resistant to wear. Among the 3 different micro dimple areal densities (5%, 10%, and 15%) tested, the lowest friction coefficient appears at 10%. Compared to the patterned UHMWPE, the wear resistance of the material is approximately 20% when compared to its unpatterned versions. In addition, it has been determined that the area density for material groups is the most effective factor on wear.