Plasma Spraying of Metal-Ceramic Composite Powders Produced by MA Method

Abstract

High performance metal matrix composite coatings could be fabricated by using the highly mixed metal-ceramic composite powders. In this study, composite powders both of Cu-Al2O3 system and of Cu-AlN system were produced by mechanical alloying (MA) method. The composite coating were made by plasma spraying of these pre-composite powders. To compare with these composite coatings, conventional coatings were made by using the conventional Cu and Al2O3 powder. The quality of the coatings obtained were evaluated by abrasion were test and the electric properties were also investigated.The main results of this study are summarized as follows, (1) In the case of spraying of MA powders, the separation of the ceramics from the metal occured due to the relative difference of specific gravity between them. Nonetheless, the sprayed coating made with MA pre-composite powders had finer microstructure and higher were resistance than made with conventional powders.(2) The electric resistivity values of the coatings made with MA powders did not scatter largely compared with those of the conventional coatings because of the homogeneous structures. Therefore, it was found that highquality composite coatings with fine and homogeneous structure can be obtained using MA powders.