Abstract
The Ni-55%Al and -20%Al composite powders were prepared by the mechanofusion process and were plasma sprayed on mild steel substrates in air. The properties of the powders and the sprayed coatings were examined, and were compared with those of several commercial powders and their coatings. The fine Al particles adhered well to the Ni core particles, but did not homogeneously coat them while mhanofusing. The mechanofused powders were found to differ from the commercial products regarding morphology and microstructure. The intermetallic compounds were not formed in the coatings in any case of air plasma spraying because of partial oxidation of the components in the powders and short reaction time for forming aluminides. The microstructure, hardness, adhesion strength and abrasive wear resistance of the coatings, which were plasma sprayed with the mechanofused powders, were almost the same as those of the coatings obtained by using the commercial powders.
