The splat morphology of nickel particles during their impact and solidification onto a stainless steel substrate were studied using both numerical simulations and experiments. In the experiments, the spraying was performed with a dc plasma torch. The torch operated at 17 kW and the argon flow rate was 33 IImin. A nickel powder was sieved to obtain a narrow particle size distribution of +53-60 Jlm with a mean particle size of 61 Jlm. The substrate was placed 310 mm from the torch and its temperature was controlled using an electric heater. In-flight particle temperatures were measured at the substrate using a ratio pyrometer. Particle tracking velocimetry was used at the spraying distance to obtain particle impact velocities. The nickel particles were sprayed onto a polished stainless steel substrate with a surface roughness of 0.04 micro meter. The substrate was heated by an electric heater and its temperature was monitored with a thermocouple. Temperatures of 20·C, 194 ·C, and 368·C were used for the stainless steel substrate. Splat imaging was performed using a scanning electron microscope (SEM) and the software package OPTIMAS was used for image analysis.

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