Influence of MoO3 on boron aluminosilicate glass-ceramic coating for enhancing titanium high-temperature oxidation resistance

The anti-oxidation behavior of boron aluminosilicate glass-ceramic materials with different MoO3 content deposited on titanium in temperatures range 850-1050 °C were investigated. The experimental results showed that in comparison with the bare titanium, the weight gain of specimen without MoO3 decreased from 18.7 to 0.6 mg/cm2 after 100 h oxidation at 850 °C.The addition of MoO3 was able to provide further decrease on the oxidation rate of titanium from 0.6 to 0.1 mg/cm2. The 20 wt.% MoO3 system measured the least weight gain and maximum tensile strength which was between the substrate and the coating for 30.1 MPa at 850 °C for 100 h whilst led to the peak retained strength value with 8.7 MPa after 30 times thermal cycles to 700 °C. The EDS line scanning images revealed that a molybdenum rich interlayer was detected in between the substrate and coating layer with average width of about 2 μm and it was believed that it did play an essential part in blocking the inward diffusion of oxygen to titanium.