|
1259 |
|
Monday, June 02, 2008, Room 04 11:50 AM Wear Protection 1 Special processes for coatings against wear, improved surface roughness of as sprayed coatings, improved sliding behavior |
|
Cavitation erosion for WC cermet coatings prepared by HVOF |
|
Hiroaki Mizuno* / FUJIMI INCORPORATED, Japan Isao Aoki / FUJIMI INCORPORATED, Japan Satoshi Tawada/ FUJIMI INCORPORATED, Japan Hiroyuki Ibe/ FUJIMI INCORPORATED, Japan Kazuto Sato/ FUJIMI INCORPORATED, Japan Junya Kitamura/ FUJIMI INCORPORATED, Japan |
|
Cavitation erosion is one of the serious problems that affect hydraulic machinery and its components. Surface modification technology is required to apply to hydraulic components, such as water turbine and radial flow pump, in general. Here, the technology, which can easily be applied to large area, is must be required for actual applications in the fields. Thus, thermal sprayed WC cermet coatings with high abrasion resistance under wet conditions are one of the promising solutions as the protective coatings against cavitation erosion. In this study, WC/Cr3C2/Ni and WC/Co/Cr coatings prepared using a high-velocity oxygen fuel (HVOF) spraying have been evaluated by a magneto-striction vibratory apparatus to investigate the cavitation erosion resistance. The microstructures of the sprayed coatings after the cavitation erosion test have been analyzed by SEM to clarify the erosion mechanism. It has been found that the cavitation erosion resistance of the WC cermet coatings is significantly affected by primary particle size of WC, powder composition and spray condition. In the composition of WC/10wt%Co/4wt%Cr, the coating with WC average particle size of 6.3 ìm sprayed by optimized conditions achieved the highest cavitation erosion resistance than the other WC coatings as well as base materials of stainless steel used in the actual components. |