Effect of Molybdenum on the Microstructure and High-Temperature Tribological Properties of Laser Clad CoCrW Coating

• Published in: Transactions of the Indian Institute of Metals Vol. 75; no. 12; pp. 3193 - 3202
• Main Authors: Han, Wenpeng, Cui, Gongjun, Cui, Haotian, Kou, Ziming, Liu, Yanping
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01.12.2022; Springer Nature B.V
• Subjects: Chemistry and Materials Science; Coating effects; Coefficient of friction; Corrosion and Coatings; High temperature; Laser beam cladding; Materials Science; Mechanical properties; Metallic Materials; Microstructure; Molybdenum; Original Article; Room temperature; Solid solutions; Solution strengthening; Tribology; Wear mechanisms; Wear rate; High temperature; Wear mechanisms; Laser cladding; Coatings; Molybdenum
• ISSN: 0972-2815; 0975-1645
• DOI: 10.1007/s12666-022-02724-0

The CoCrW coating modified with 11.0 wt% Mo was prepared by using laser cladding. Meanwhile, the effect of molybdenum on the microstructure and high-temperature tribological properties of coatings was systematically investigated. Tribological tests of coatings were conducted by using a ball-on-disk tribo-tester from 23 to 1000 °C against Si 3 N 4 ball. The Mo showed a solid solution strengthening effect on the coating and promoted the formation of carbides. The phases of the CoCrW-11%Mo coating were composed of γ (fcc), Cr 7 C 3 , Cr 23 C 6 , Co 6 Mo 6 C and Co 3 Mo and the hardness of the coating was 1.3 times higher than that of CoCrW coating. The friction coefficients of the coatings decreased with the rise of temperature. The wear rates initially increased and then decreased with the increase in temperature. The Mo-modified coating had better tribological properties than the unmodified coating from room temperature to 1000 °C. The coatings showed different wear mechanisms at different temperatures.