Laser Cladding 공정으로 제조된 Tribaloy T-800 코팅 소재의 미세조직 및 용융 Al 침식 특성

초록

A T-800 (Co-Mo-Cr) coating material is fabricated using Co-Mo-Cr powder feedstock and laser cladding. The microstructure and melted Al erosion properties of the laser-cladded T-800 coating material are investigated. The Al erosion properties of the HVOF-sprayed MoB-CoCr and bulk T-800 material are also examined and compared with the laser-cladded T-800 coating material. Co and lave phases (Co2MoCr and Co3Mo2Si) are detected in both the lasercladded T-800 coating and the bulk T-800 materials. However, the sizes of the lave phases are measured as 7.9 μm and 60.6 μm for the laser-cladded and bulk T-800 materials, respectively. After the Al erosion tests, the erosion layer thicknesses of the three materials are measured as 91.50 μm (HVOF MoB-CoCr coating), 204.83 μm (laser cladded T- 800), and 226.33 μm (bulk T-800). In the HVOF MoB-CoCr coating material, coarse cracks and delamination of the coating layer are observed. On the other hand, no cracks or local delamination of the coating layer are detected in the laser T-800 material even after the Al erosion test. Based on the above results, the authors discuss the appropriate material and process that could replace conventional bulk T-800 materials used as molten Al pots.

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