Effect of Ga(NO 3 ) 3 doping on the characteristics of TC23 micro-arc oxidation film

Abstract

The micro-arc oxidation of TC23 titanium alloy was carried out by adding different concentrations of Ga(NO₃)₃ to the silicate-phosphate composite electrolyte system. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical workstation were used to study the changes of microscopic morphology, phase composition and corrosion resistance of micro-arc oxide film after the addition of Ga(NO₃)₃. The results show that the addition of Ga(NO₃)₃ to the basic electrolyte can improve the oxidation voltage, improve the microstructure of the micro-arc oxidation film, reduce the roughness of the film surface, and Ga³⁺ participates in film formation in the form of a hard phase Ga₂O₃, which improves the hardness and corrosion resistance of the film. When the concentration of Ga(NO₃)₃ is 0.1 g/L, the hardness and bonding force of the micro-arc oxidation film prepared are the highest, reaching 454.9HV and 11.3N, respectively, and the lowest corrosion rate in the 3.5% NaCl corrosion solution is 1.132 × 10⁻² mpy, and the micro-arc oxidation film has the best characteristics.