Properties of the surface layer after high-energy treatment by powder particles

Abstract

Experiments were conducted on high-energy surface treatment of a structural steel substrate with a flow of tungsten, nickel, and titanium nitride powder particles. The impact pressure of the steel target and particles accelerated by explosion energy was estimated using the momentum conservation equation and the linear equation of the particle material shock adiabat. It was found that the impact pressure of the target and particles is 62 GPa for a tungsten particle, 48 GPa for a nickel particle, and 41 GPa for a titanium nitride particle. The heating temperature of particles during their collision with the steel target surface was calculated taking into account the conditions of mass and momentum conservation at the shock wave front. The maximum heating temperature of particles at the point of their collision with the substrate surface (at a particle velocity of 2000 m/s) is 1103 K for tungsten particles, 755 K for nickel particles, and 589 K for titanium nitride particles. It was shown that the steel target strength increases when it is subjected to high-energy treatment with a flow of particles. The maximum hardening of the steel target surface layer increases by 32–55 % compared to initial microhardness and is observed at a depth of 2–4 mm from the treatment surface. Then it decreases to the value of starting material microhardness (170 HV) at a distance of 15–20 mm from the treated surface.