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3695 |
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Investigation on microstructure and wear performance of in-situ synthesized TaC particles reinforced laser cladding NiCrBSi coatings |
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Yu-Yue Wang* / State Key Laboratory for Mechanical Behavior of Materials, Xian Jiaotong University, China Y.-N. Lai / State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China C.-J. Li/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University,, China G.-J. Yang/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University,, China |
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In-situ synthesized ceramic particles reinforced laser cladding composite coating is a novel composite coating combining laser cladding process and in-situ synthesis technology, which can form ceramic particles in composite coating via in-situ synthesis in order to overcome the drawbacks of bad wettability of ceramic to alloys. TaC has excellent properties such as high melting point, high hardness, high resistance to corrosion and oxidation. TaC is a promising addition in composite coatings to reinforce coating. In this paper, fine TaC particles were in situ synthesized in a laser cladding NiCrBSi alloy coating by a pre-coating method. The microstructure and metallographic analyses were performed by SEM, EDS and XRD. The influences of TaC particles size and volume percentage on microstructure, microhardness and abrasive wear resistance were investigated. The results show that in-situ synthesized and remained TaC particles with two-scale of nano-size and micro-size are dispersed homogeneously in the laser cladding NiCrBSi composite coatings. Addition of TaC extremely compresses the formation of brittle carbides such as M7C3 and eutectic of (Ni+M23C6). TaC particles act as hard phases, improving the microhardness of the composite coating. And the decrease of brittle carbide reduces the crack susceptibility of composite coating. The microhardness of TaC-NiCrBSi coatings is increased with increasing the size and volume percentage of TaC particles. The abrasive wear resistance of coatings is decreased after it reaches peek value due to the exfoliation of TaC particles. |