Thermal Stability and Degradation Properties of Aluminide Coated and Uncoated Ti-6Al-4V Alloys Exposed to High Temperature Flame

摘要: The thermal stability of aluminide coated and uncoated Ti-6Al-4V(Ti-64) titanium alloys in high temperature flame environments has been investigated. The pack cementation method was used to apply the aluminide coatings. The TiAl3 layer was formed after heat treatment of coated pure Titanium and Ti alloys at 500 °C–700 °C. After being exposed to a high temperature flame, the uncoated titanium alloys formed TiO2 and Al2O3, resulting in a significant weight gain and the loss of the original shape. However, when the aluminide coated titanium alloys were exposed to the flame, a thin layer of Al2O3 was produced as a result of the flame exposure, and the coated specimens maintained their original shape in high temperature flame environments when exposed at ~ 1360 °C for 15 min. The detailed mechanisms for flame resistance of coated specimens, as well as microstructural observations were examined. The …