Effect of Pre-oxidation on Low-temperature Oxidation Behaviors of TiC-TiB_2/MoSi_2 Composite

The oxidation behaviors of both 20vol%TiC-TiB2/MoSi2 composite and pre-oxidation treatment material at 500 ℃ were investigated.The results show that the mass gains of the composite is increased by 1.67 mg·cm-2 when oxidized at 500 ℃ for 240 h,and the oxidation cure nearly obeys the linear law.The loose oxidation scale is formed on the materials surface and the "pesting" appears.When the oxidation time reaches 240 h,the mass gains of the samples by pre-oxidation treatment at 1200 ℃ is only increased by 0.062 mg·cm-2,and the pest is restrained.The TiO2 and SiO2 multiple scales formed by pre-oxidation treatment on TiC-TiB2/MoSi2 composite surface can effectively improve the low-temperature oxidation resistance.