REAEARCH PAPER |
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Effect of Low Pressure Sintering Temperature on Microstructure and Mechanical Performance of Ultrafine WC-Co Based Hard Metals Prepared by One-step Method |
BAO Xianyong1,2, ZHANG Feng2, LU Zhongchen3, ZENG Meiqin1, ZHU Min1
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1 School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640; 2 Fiyta Holdings LTD, Shenzhen 518057; 3 School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 |
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Abstract W-C-10Co-0.9VC-0.3Cr3C2 nano composite powders were prepared by plasma milling (P-milling), and subsequently compressed into green compacts with a uniaxial pressure, then the green compacts were carbonized and sintered in a one-step me-thod by low pressure sintering technology. The analysis results indicate that the homogeneous and lamellar structure composite powder is achieved by P-milling for 3 h. Due to the special effect of P-milling, VC and Cr3C2 begin to play a role of inhibition to WC grain size at the temperature of 1 380 ℃ and 1 400 ℃. Among them, the hard metals that sintered at 1 380 ℃ exhibit the optimum combination of WC grain size and relative density, and the best mechanical performance simultaneously. The density of hard metal is 99.2% with 250 nm of mean WC grain size, and the hardness and transverse rupture strength reach up to 92.3HRA and 2 443 MPa, respectively.
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Published: 25 August 2017
Online: 2018-05-07
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