Particle impact ignition-resistance of a ductile phase toughened glass-ceramic coating

Particle impact ignition is a threat to metal components in high-pressure oxygen environments, where particles can strike metal surfaces at high velocities and ignite. In this work, we examine the ability of an oxygen-compatible environmental barrier coating (ox-EBC), made from interpenetrating Ni and glass-ceramic constituents, to prevent impact-driven particle ignition. Through laser-induced particle impact testing (LIPIT) in oxygen, we find that ignition of Ti-6Al-4V particles requires a higher impact velocity on an ox-EBC target than on targets of Ni or Al 2 O 3 . Additionally, the coefficient of restitution for Ti-6Al-4V impact on the ox-EBC is greater than for impact on Ni or Al 2 O 3 , indicating that comparatively little plastic deformation and temperature rise occurs during impact on the ox-EBC. Through finite element analysis, we establish that these behaviors result from the low dynamic yield strength and high modulus of resilience of the ox-EBC, enabling conversion of a large amount of impact energy to recoverable elastic strain energy. Together with previous work, these results demonstrate that the ox-EBC exhibits several key properties required of protective coatings for oxygen-rich turbomachinery: its interpenetrating structure enhances toughness while the glass phase provides oxidation resistance and stores elastic energy during impact to inhibit particle ignition. • Particle impact ignition behaviors of a ductile phase-toughened glass-ceramic environmental barrier coating (ox-EBC) were assessed using experiments and simulations • Laser-induced particle impact testing in 1 atm pure oxygen was used to observe the ignition of individual Ti64 particles impacting targets of Al 2 O 3 , Ni, and the ox-EBC • The respective critical impact velocities for particle ignition on Al 2 O 3 , Ni, and the ox-EBC are 350 m/s, 400 m/s, and 460 m/s • Particle impact on the ox-EBC exhibits a greater coefficient of restitution than impact on Ni or Al 2 O 3 , suggesting that impact on the ox-EBC leads to less overall plastic deformation and adiabatic heating in the particle • The ox-EBC effectively suppresses particle ignition because of its high modulus of resilience, which helps store recoverable elastic strain energy upon particle impact, and its relatively low yield strength, comparable to that of the metallic particle