Study on Morphological Structure and Wear Resistance of Porous Coatings on the Surface of Joint Implants
Objective To analyze and explore the morphological structure,and wear resistance of porous coatings with different processes on the surface of joint implants.Methods Three types of plasma sprayed titanium coating samples,one type of titanium bead sintered coating sample,and one type of 3D printed porous structure sample were selected.The porous structure of the surface coating of the samples were analyzed according to YY/T 0988.14-2016,and the porosity and pore intercept of the porous structure were measured on the longitudinal section of coating under metallographic microscope.And the wear resistance of the samples were tested according to ASTM F1978-22.The surface morphology of the coating before and after wear were observed under a scanning electron microscope,and the wear behavior and wear mechanism of coatings with different processes and pore structures were analyzed.Results The porosity of several coatings ranged from 30%to 60%,with a pore intercept between 100 and 510 μm,in compliance with FDA regulations,the pore connectivity of titanium bead sintered coatings and 3D printed porous coatings were better than that of plasma sprayed coatings.The wear process of plasma sprayed coatings was characterized by particle detachment accompanied by abrasive wear,while the wear process of titanium bead sintered coatings and 3D printed porous samples was mainly characterized by abrasive wear.Conclusion The difference in wear resistance is significantly related to coating process,porosity,and structural form.