Effect of Ti3SiC2 particles addition on friction and oxidation behavior at high temperature of micro-arc oxidation layer on TC4 alloy

This study involved the preparation of TiO2 layers enhanced with the Ti3SiC2 phase. This was achieved by incorporating Ti3SiC2 particles (2-8 g/L) into an Na2WO4+Na2SiO3+Na3PO4 electrolyte system, utilizing the micro-arc oxidation (MAO) technique. The phase composition of the MAO layer was analyzed by X-ray diffractometer, the surface porosity and elemental distribution were assessed via scanning electron microscopy and energy dispersive spectroscopy; the cross-sectional thickness of the MAO layer was measured by metallurgical microscope; and the surface flatness was measured by confocal microscope. The friction behavior of the MAO layer with different Ti3SiC2 contents was compared by sliding wear tests; anti-oxidation tests was used to evaluate the oxidation resistance of the layers. The results show: 1) The addition of Ti3SiC2 particles with higher concentrations can increase the thickness of MAO layer, improve the existence of numerous “volcanoes” and large-sized pores in the MAO layer and play a certain “pore sealing” effect. 2) When the concentration of Ti3SiC2 is greater than 4g/L, the friction and wear behavior of the MAO layer is enhanced; 3) After oxidation at 700℃ for 14 h, the MAO layer with higher concentration (6~8g/L) showed better oxidation resistance. The Ti3SiC2 in the layer would work together with the atoms in Ti to block the entry of external oxygen atoms.