Effect of processing parameters on copper powder produced by novel hybrid atomisation technique

ABSTRACT

In the present work, a novel design of centrifugal atomiser for producing pure copper powder was studied. The novel complementary hybrid system provides an external stream of gas to increase the cooling rate of the atomised particles. Effects of the operating parameters, such as disc rotating speed and gas flowrate on the morphology, particle size distribution, cooling rate and microstructure, were analysed. It was evidenced from the experimental results that the median particle size in the novel atomisation process is mainly controlled by centrifugal disintegration. The microstructure of the produced powders was equiaxed and the grain size decreased with increasing gas flowrate. The cooling rate experienced by centrifugal atomised Cu powders was studied via numerical formulation estimated to be 10⁴–10^6?K?s^?1. The results show that the cooling rate is a strong function of particle size and increasing the rotating disc speed also increased the cooling rates.