| WC-Co계 미세조직에 따른 CVD 다이아몬드 코팅막의 접착력 변화 |
| 이동범, 채기웅 |
| 호서대학교 신소재공학전공 |
| Dependence of the Diamond Coating Adhesion on the Microstructure of WC-Co Substrates |
| Dong-Beum Lee, Ki-Woong Chae |
| Department of Materials Science and Engineering, Hoseo University |
|
|
|
|
|
| ABSTRACT |
|
The effect of microstructure of WC-Co substrates which have different WC grain sizes from submicron to 5 $mu$m on the diamond-substrate adhesion strength was investigated. The substrates were pre-treated by two methods : chemical etching with Murakami's solution and subsequently with $H_2SO_4$, and thermal heat-treatment. The adhesion strength was estimated by degree of peeling after Rockwell indentation. Diamond films of 20 $mu$m thickness deposited on the heat-treated substrates showed an excellent adhesion strength at the load of 100 kg, which ascribed to the large and elongated WC grains. However, the cutting edge of insert was deformed after heat treatment and the surface morphology of heat treated substrate strongly affected on the surface roughness of the deposited diamond films. On the contrary, the diamond film of 10 $mu$m in thickness on the chemically etched substrates of average WC grain size over 2 $mu$m showed good adhesion strength enough not to peel-off under a load of 60 kg. Especially, the substrate of average WC grain size over 5 $mu$m exhibited much improved reliability of adhesion comparing with the substrate of average grain size under 2 $mu$m. No substrate deformation was observed in this case after the chemical etching, which is more advantageous and more practical in terms of precious machining than the heat treatment case. |
| Key words:
Adhesion strength, Diamond coating, Chemical etching, Heat treatment, WC |
|
|
|
PDF Links 
Full text via DOI
Download Citation 
