Abstract
Composite powder materials possess a potential to fabricate the high performance structural coatings instead of the conventional mechanically mixing powders. In the many composite powder making processes, machanical alloying (MA) process enables to obtain the homogeneous microtructure of metal/ceramic materials system. In the DC plasma spraying of metal/ceramic MA composite powders, separation phenomena of ceramic phase from metal phase has been recognized.
In this study, metal/ceramic MA composite powders were made by using the ceramic making original elements as the starting material and these MA powders were plasma sprayed. Possibility of fabrication of ceramic particles dispersed composite coatings, by the inter-diffusion of these starting elements, was investigated.
The main results obtained in this work are summarized as follows:
(1) Separation was recognized even in the Cu/TiC MA powder material system, which had good wettability between metal and ceramic materials.
(2) Separation is basically caused in MA composite powder materials under the spraying conditions of high power level, on which both materials can be fully melted.
(3) TiC dispersed homogeneous coating was made by DC plasma spraying of Cu/Ti/C MA powder.
(4) Coating made from MA powders showed slightly higher hardness with less scattering compared with that made from the conventional powders, because of the homogeneously dispersed structures.
