High-temperature phase stability and tribological properties of laser clad Mo{sub 2}Ni{sub 3}Si/NiSi metal silicide coatings
- Laboratory of Laser Materials Processing and Surface Engineering, School of Materials Science and Engineering, Beihang University (China)
Mo{sub 2}Ni{sub 3}Si/NiSi wear-resistant metal silicide composite coatings consisting of Mo{sub 2}Ni{sub 3}Si primary dendrite and interdendritic Mo{sub 2}Ni{sub 3}Si/NiSi eutectic were fabricated on substrate of an austenitic stainless steel AISI321 by laser cladding using Ni-Mo-Si elemental powder blends. The high-temperature structural stability of the coating was evaluated by aging at 800 deg. C for 1-50 h. High-temperature sliding wear resistance of the as-laser clad and aged coatings was evaluated at 600 deg. C. Results indicate that the Mo{sub 2}Ni{sub 3}Si/NiSi metal silicides coating has excellent high temperature phase stability. No phase transformation except the dissolution of the eutectic Mo{sub 2}Ni{sub 3}Si and the corresponding growth of the Mo{sub 2}Ni{sub 3}Si primary dendrite and no elemental diffusion from the coating into the substrate were detected after aging the coating at 800 deg. C for 50 h. Aging of the coating at 800 deg. C leads to gradual dissolution of the interdendritic eutectic Mo{sub 2}Ni{sub 3}Si and subsequent formation of a dual-phase structure with equiaxed Mo{sub 2}Ni{sub 3}Si primary grains distributed in the NiSi single-phase matrix. Because of the strong covalent-dominated atomic bonds and high volume fraction of the ternary metal silicide Mo{sub 2}Ni{sub 3}Si, both the original and the aged Mo{sub 2}Ni{sub 3}Si/NiSi coating has excellent wear resistance under pin-on-disc high-temperature sliding wear test conditions, although hardness of the aged coating is slightly lower than that of the as-clad coating.
- OSTI ID:
- 20634798
- Journal Information:
- Acta Materialia, Vol. 52, Issue 18; Other Information: DOI: 10.1016/j.actamat.2004.08.006; PII: S1359-6454(04)00473-2; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 1359-6454
- Country of Publication:
- United States
- Language:
- English
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