THERMAL ANALYSIS OF THE PARTICLE CRITICAL VELOCITY ON BONDING EFFICIENCY IN COLD GAS DYNAMICS SPRAY PROCESS.

摘要

This paper presents a numerical analysis of the particle critical velocity on the bonding efficiency in Cold Gas Dynamic Spray (CGDS) process by using ABAQUS/CAE 6.9-EF1. The particle impact temperature in CGDS is one of the most important factors that can determine the properties of the bonding strength to the substrate. In the CGDS process, bonding occurs when the impact velocity of particles exceed a critical velocity [1], which can reach minimum interface temperature of 60% of melting temperature in °C [2]. The critical velocity depends not only on the particle size, but also the particle material. Therefore, critical velocity should have a strong effect on the coating quality. In the present numerical analysis, impact velocities were increased in steps of 100 m/s from the lowest simulated impact velocity of 300 m/s. This study illustrates the substrate deformations and the transient impact temperature distribution between particle(s) and substrate. In this paper, an explicit numerical scheme was used to investigate the critical velocity of different sizes of particle during the bonding process.Finally, the computed results are compared with the experimental data. Copper particles (Cu) and Aluminum substrate (Al) were chosen as the materials of simulation.