Optimum Technique Parameters of Biological Ceramic Coating's Preparation by Constant Current Micro-arc Oxidation on Titanium Alloy Surface

Bioceramic coatings were prepared on TC4 titanium alloy surface by constant current micro-arc oxidation. The optimum preparation parameters and properties of the coatings were studied. Response surface methodology was applied to design the processing parameters of constant current micro-arc oxidation. In addition, surface roughometer, microhardness tester, XRD and SEM were also used to analyze the roughness, microhardness, phase composition and surface morphology of the coatings. And the property change of the coatings was discussed with different processing parameters. Results show that when the Ca/P ratio is 1, the forward current 2.5 A, time 15 min, and the frequency 750 Hz, the thickness of the bioceramic coating is 119.3 mu m, the roughness 5.1 mu m, and the hardness 10407.8 MPa. The surface of the coating is rough and porous with uniformly-distributed pores.