M. Boulos, X. Fan, Tekna Plasma Systems Inc., Sherbrooke, QC, Canada; O. Kovárík, Czech Technical University, Praha 2, Czech Republic; G. Masini, University of Bologna, Bologna, Italy
To prepare a dense, defect-free deposit of refractory metals relies not only on the droplets’ state, their temperature and velocity prior to impact on the surface of substrate and/or the precedent deposited layer, but also on the surface temperature of the substrate, whereupon the droplets impact. This paper presents a comprehensive investigation, in which the particles temperature, velocity, and the substrate temperature are studied all-in-one step to understand their influence on the deposit quality. The experimental results make our knowledge of the induction plasma spray of refractory metals process more integrated. Based on our estimation on the effect of all of the three factors, a set of optimized process parameters were then established and proved by applying it in producing stationary deposits and coating layers. The results obtained distinguish the induction plasma spray a unique technique, which is ideal to be utilized in refractory metals deposit.
