Ignition resistance performance and its mechanism of TC11 titanium alloy for aero-engine

The effect of friction contact pressure P and oxygen concentration c(0) of premixed air flow on the ignition resistance of TC11 titanium alloy was studied by frictional ignition test. The relationship P-c(0) quantitatively describing the ignition resistance of TC11 was established and the microscopic mechanism of ignition and ignition resistance of TC11 was provided by in-situ observation, SEM and EDS, etc. The results show that the relationship P-c(0) of TC11 obeys parabolic rule. When P increases from 0.05MPa to 0.25MPa, the c(0) required for ignition decreases by about 32.5%. The c(0) of TC11 ignition is 20% higher than that of TC4 at least, i.e., the ignition resistance performance of TC11 is obviously higher than that of TC4. The violent sparks appeared during friction process, and the origin of ignition was located at the micro-bump which has a fresh surface. During ignition, four distinct zones form, including combustion zone, fusion zone, heat-affected zone and transitional zone. The diffusion rate of