The microstructure, hardness, and wear behaviors of a High Velocity Oxygen Fuel(HVOF) sprayed WC-CoFe coating are comparatively investigated before and after laser heat treatments of the coating surface. During the spraying, the binder metal is melted and a small portion of WC is decomposed to W2C. A porous coating is formed by evolution of carbon oxide gases formed by the reaction of the free carbon and the sprayed oxygen gas. The laser heat treatment eliminates the porosity and provides a more densified microstructure. After laser heat treatment, the porosity in the coating layer decreases from 1.7% to 1.2 and the coating thickness decreases from 150 μm to 100 μm. The surface hardness increases from 1440 Hv to 1117 Hv. In the wear test, the friction coefficient of coating decreases from 0.45 to 0.32 and the wear resistance is improved by the laser heat treatment. The improvement is likely due to the formation of oxide tribofilms.

Abstract
 1. 서 론
 2. 실험 방법
  2.1 시편제작
  2.2 코팅층 분석
 3. 결과 및 고찰
  3.1 분말의 특성
  3.2 최적용사코팅 및 레이저 열처리 코팅의 결정구조
  3.3 레이저 열처리 전 후 코팅층의 미세구조
  3.4 레이저 열처리 전 후 코팅층의 특성
  3.5 최적용사코팅 및 레이저 열처리 코팅의 마찰마모 특성
 4. 결 론
 References

• 주윤곤(창원대학교 메카트로닉스 융합부품소재 연구센터(ERC)) | Yunkon Joo (Engineering Research Center(ERC) for Integrated Mechatronics Materials and Components, Changwon National University)
• 윤재홍(창원대학교 신소재공학부) | Jaehong Yoon (Department of Materials Science and Engineering, Changwon National University)
• 이재현(창원대학교 신소재공학부, 창원대학교 메카트로닉스 융합부품소재 연구센터(ERC)) | Jehyun Lee (Department of Materials Science and Engineering, Changwon National University, Engineering Research Center(ERC) for Integrated Mechatronics Materials and Components, Changwon National University) Corresponding author