Role of interface in burn of titanium alloys

Titanium fire found in advanced aircraft engines has attracted interesting attentions. Influences of interface on the burning behavior are important. The results reveal that the interface between burning products and air is cracks and porous, which can not retard oxygen diffusion into the matrix and the burn. The interface between burning products and matrix for C. P. Ti and Ti-6-4 is also cracks and porous, however the interface of Ti40 alloy is tenacious, which is in the form of Cr₂O₃, and this product can retard oxygen diffusion into the matrix and reduces the burning velocity. Thereby burn resistant mechanism of suspending oxygen diffusion is put forward.