Friction-induced temperature rise at energetic β-HMX crystal interfaces: Part I. Role of contact pressure and speed under dry sliding friction

In this study, the friction behavior and surface temperature of beta-phase octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (β-HMX), a widely used energetic crystal in modern weapon industry, is systematically investigated by varying the contact pressure and sliding speed as well as sliding cycles. Experimental results reveals that the maximum temperature rise on β-HMX surface can be well-correlated with the frictional power density involving the friction coefficient and contact pressure and sliding speed. The frictional work-heat conversion rate of β-HMX surface decreases with the frictional power density and then stabilized at ∼43.7 % upon single scratch and it decreases with sliding cycles upon reciprocating scratch. These findings can provide deep insights into the frictional safety of energetic materials.