|
1894 |
|
Effects of WC particle size on deposition of cold spray WC-Co coatings |
|
Siao Ming Ang / Swinburne University of Technology, Australia James Wang / Swinburne University of Technology, Austarlia Christopher Berndt/ Swinburne University of Technology, Australia Philip Cheang/ SIM University, Singapore |
|
Cold spray is a material deposition process that uses a high pressure, high velocity gas jet for the deformation and bonding of particles. However, attempts to deposit brittle or hard materials such as ceramics have not been successful unless they are co-deposited with a ductile matrix material. This paper examines the WC particle size influencing the deposition of Co based cermet coatings. Micron-structured powder and nano-structured powders with similar Co content was used in the experiments. It was observed that varying the WC particle size resulted significant effect on the deposition efficiency of the coating. Micron-structured WC-Co coatings achieve no coating build up when given the same or elevated conditions compared to the nano-structured WC-Co coatings. In addition, micron-structured WC-Co coatings exhibited erosion and deposition effect on the substrate surface. Finer WC particles (<1 ìm) were found close to the substrate interface and larger WC particles (1-2 ìm) at the coating surface. These observations postulated that there is a critical WC particle size for deposition by cold spray. This could be due to the effect of WC particle size on the formation and cohesion of the coating layer. |