Combustion characteristics and surface damage mechanism of TC11 titanium alloy under high-speed rubbing

Titanium alloys have great potential for applications in the aviation industry. However, they have high combustion sensitivity and can ignite when subjected to rubbing. Therefore, this study investigated the combustion characteristics and surface damage mechanism of TC11 alloy using a high-speed rubbing experiment. The critical ignition conditions, including the ignition temperature and critical pressure, were examined at different rotational speeds and loads. The critical ignition pressure and temperature decreased as the rotational speed and load increased. Moreover, the rubbing damage changed from abrasive and adhesive wear to oxidative wear. At the moment of ignition, numerous spalls, cracks, and molten structures were observed on the surface of the alloy, which facilitated the transportation of oxygen into the matrix. The morphology and composition of post- combustion samples of the alloy were investigated. Accumulation of aluminum and molybdenum at the at the solid-liquid interface hindered the external diffusion of titanium and oxygen, thereby preventing the spread of combustion. Overall, this study contributes to a better understanding of the combustion behavior of titanium alloys, which can guide the design and development of titanium components for applications such as aircraft engines.