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Zhao X, Zhong Q, Zhai P, Fan P, Wu R, Fang J, Xiao Y, Jiang Y, Liu S, Li W. Microstructure and Wear Resistance of Laser-Clad Ni-Cu-Mo-W-Si Coatings on a Cu-Cr-Zr Alloy. MATERIALS (BASEL, SWITZERLAND) 2022; 16:284. [PMID: 36614623 PMCID: PMC9822329 DOI: 10.3390/ma16010284] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/13/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
To improve the wear resistance of high-strength and high-conductivity Cu-Cr-Zr alloys in high-speed and heavy load friction environments, coatings including Ni-Cu, Ni-Cu-10(W,Si), Ni-Cu-10(Mo,W,Si), and Ni-Cu-15(Mo,W,Si) (with an atomic ratio of Mo,W to Si of 1:2) were prepared using coaxial powder-feeding laser cladding technology. The microstructure and wear performance of coatings were chiefly investigated. The results revealed that (Mo,W)Si2 and MoNiSi phases are found in the Ni-Cu-10(Mo,W,Si) and Ni-Cu-15(Mo,W,Si) coating. WSi2 phases are found in the Ni-Cu-10(W,Si) coating. The degree of grain refinement in Ni-Cu-10(Mo,W,Si) was greater than that of the Ni-Cu-10(W,Si) coating after the effect of Mo. The excellent wear resistance and micro-hardness of the Ni-Cu-15(Mo,W,Si) coating were attributed to the increase in its dispersion phase, which were approximately 34.72 mg/km and 428 HV, 27.1% and 590% higher than the Cu-Cr-Zr substrate, respectively. The existence of silicide plays an important role in grain refinement due to the promotion of nucleation and the inhibition of grain growth. In addition, the wear mechanism transformed from adhesive wear in the Ni-Cu coating with no silicides to abrasive wear in the Ni-Cu-15(Mo,W,Si) coating with high levels of silicides.
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Affiliation(s)
- Xiaojun Zhao
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
- Key Laboratory of Non-Ferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China
| | - Qi Zhong
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - Pengyuan Zhai
- New Technology Promotion Institute of China Ordnance Industries, Beijing 100089, China
| | - Pengyu Fan
- New Technology Promotion Institute of China Ordnance Industries, Beijing 100089, China
| | - Ruiling Wu
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - Jianxiao Fang
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - Yuxiang Xiao
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - Yuxiang Jiang
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - Sainan Liu
- School of Resource Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Wei Li
- Powder Metallurgy Institute, Central South University, Changsha 410083, China
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Normalizing Effect of Heat Treatment Processing on 17-4 PH Stainless Steel Manufactured by Powder Bed Fusion. METALS 2022. [DOI: 10.3390/met12050704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Laser powder bed fusion (L-PBF)-processed 17-4 PH stainless steel (SS) generally exhibits a non-equilibrium microstructure consisting mostly of columnar δ-ferrite grains and a substantial fraction of retained austenite and martensite, contrary to 17-4 PH SS wrought with a fully martensite structure and coarse grains. Despite the different microstructures of L-PBF and wrought 17-4 PH SS, post-processing is typically performed using the conventional heat treatment method. The insufficient effect of the heat treatment on the L-PBF product produces a δ-ferrite phase in the microstructure. To obtain improved mechanical properties, the addition of a normalizing treatment to the conventional heat treatment after L-PBF in a nitrogen gas environment was investigated. The fully martensitic matrix developed by adding the normalizing treatment contained homogeneous Cu precipitates and exhibited a similar or improved strength and elongation to failure compared to the wrought SS.
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