Experimental study and mathematical modeling of the processes occurring in zrn coating/silumin substrate systems under pulsed electron beam irradiation

Abstract

This paper presents a study of a combined modification of silumin, which included deposition of a ZrN coating on a silumin substrate and subsequent treatment of the coating/substrate system with a submillisecond pulsed electron beam. The local temperature on the samples in the electron-beam-affected zone and the thickness of the melt zone were measured experimentally and calculated using a theoretical model. The Stefan problem was solved numerically for the fast heating of bare and ZrN-coated silumin under intense electron beam irradiation. Time variations of the temperature field, the position of the crystallization front, and the speed of the front movement have been calculated. It was found that when the coating thickness was increased from 0.5 to 2 µm, the surface temperature of the samples increased from 760 to 1070◦C, the rise rate of the surface temperature increased from 6 × 107 to 9 × 107 K/s, and the melt depth was no more than 57 µm. The speed of the melt front during the pulse was 3 × 105 µm/s. Good agreement was observed between the experimental and theoretical values of the temperature characteristics and melt zone thickness.