Study on oxidation behavior of spark plasma sintered TiB2[sbnd]SiC ceramic under laser irradiation

Abstract

In this paper, TiB2SiC ceramic with a Vickers hardness of 24.6 ± 0.8 GPa is prepared by spark plasma sintering. A novel method of using laser-induced oxidation to assist micro milling of the TiB2SiC ceramic is proposed. The microstructure and phase composition of the material after laser irradiation are studied. The oxidation mechanism is revealed. Under laser irradiation, an oxidation reaction between ceramic and oxygen takes place, forming a loose and porous oxide layer which is easy to remove. The effects of average laser power, scanning speed and reaction environment on the oxidation behavior of TiB2SiC ceramic are investigated in detail. The results indicate that the thickness of the oxide layer increases with an increase in the average laser power and a decrease in the scanning speed. A thick and stable oxide layer is formed in an oxygen-rich environment. The thickness of the subsurface layer is independent of the reaction environment. For the investigated range of parameters, the optimal laser parameters are average power of 5 W and scanning speed of 1 mm/s, under which the thicknesses of oxide and subsurface layers are 51 μm and 15 μm, respectively, in an oxygen-rich environment.