Preparation of Ti-Al-Si Gradient Coating Based on Silicon Concentration Gradient and Added-Ce
Zihan Wang, Faguo Li, Xiaoyuan Hu, Wei He, Zhan Liu, Yao Tan
Abstract
Titanium and titanium alloys have excellent physical properties and process properties and are widely used in the aviation industry, but their high-temperature oxidation resistance is poor, and there is a thermal barrier temperature of 600 °C, which limits their application as high-temperature components. The Self-generated Gradient Hot-dipping Infiltration (SGHDI) method is used to prepare the Ti-Al-Si gradient coating based on the silicon concentration with a compact Ti(Al,Si)3 phase layer, which can effectively improve the high-temperature oxidation resistance of the titanium alloy. Adding cerium can effectively inhibit the generation of the τ2: Ti(AlxSi1−x)2 phase within a certain hot infiltration time so as to form a continuous dense Al2O3 layer to further improve the oxidation resistance of the coating. Studies have found that multiple Ti-Al binary alloy phase layers are formed during the high-temperature oxidation process, which has the effect of isolating oxygen and crack growth, and effectively improving the high-temperature resistance of the coating oxidation performance.