Wetting and pressureless infiltration behavior of Cu/316L system at 1100°C

Abstract

It is still one of the great challenges to fully understand the coupling of reactive infiltration kinetics and wetting mechanism in the pressureless infiltration processes. We studied the wetting and pressureless infiltration behavior of Cu on 316L substrate with different pore sizes and porosity at 1100 °C under high vacuum by using the sessile drop method. The initial contact angle of Cu/316L system is ∼ 26 °, and rapid spreading (in ∼1.35 s) occurs under the action of capillary force due to the dissolutive wetting mechanism. The passivated film (Cr2O3) on the surface of 316L stainless-steel removed by self-cleaning reaction and interface reaction accompanying CrO gas phase release. Further, the obstacles of wetting and infiltration were eliminated. The reactive infiltration kinetics of Cu/316L cannot be predicted by the Washburn equation, preferring to an exponential variation. The infiltration kinetics is consistent with the wetting kinetics of melt on the smooth substrate surface, that is, the infiltration kinetics is limited by the dissolution kinetics.