Korean Journal of Materials Research, Vol.30, No.12, 672-677, December, 2020
펄스전류활성 소결 공정을 이용한 Ni 함량변화에 따른 WC 소재의 특성평가
Characteristic Evaluation of WC Hard Materials According to Ni Content Variation by a Pulsed Current Activated Sintering Process
E-mail:
Expensive PCBN or ceramic cutting tools are used for the processing of difficult-to-cut materials such as Ti and Ni alloy materials. These tools have a problem of breaking easily due to their high hardness but low fracture toughness. To solve this problem, cutting tools that form various coating layers are used in low-cost WC-Co hard material tools, and researches on various tool materials are being conducted. In this study, WC-5, 10, and 15 wt%Ni hard materials for difficult-to-cut cutting materials are densified using horizontal ball milled WC-Ni powders and pulsed current activated sintering method (PCAS method). Each PCASed WC.Ni hard materials are almost completely dense, with a relative density of up to 99.7 ~ 99.9 %, after the simultaneous application of pressure of 60 MPa and electric current for 2 min; process involves almost no change in the grain size. The average grain sizes of WC and Ni for WC-5, 10, and 15 wt%Ni hard materials are about 1.09 ~ 1.29 and 0.31 ~ 0.51 μm, respectively. Vickers hardness and fracture toughness of WC-5, 10, and 15 wt%Ni hard materials are about 1,923 ~ 1,788 kg/mm2 and 13.2 ~ 14.3 MPa.m1/2, respectively. Microstructure and phase analyses of PCASed WC-Ni hard materials are performed.
Keywords:pulsed current activated sintering process;WC-Ni;hardness;fracture toughness;rapid sintering
- Lee JH, Oh IH, Jang JH, Hong SK, Park HK, J. Alloy. Compd., 786, 1 (2019)
- Lee JH, Park HK, Jang JH, Oh IH, Met. Mater. Int., 25, 268 (2019)
- Kim JH, Lee JH, Jang JH, Oh IH, Hong SK, Park HK, Korean J. Met. Mater., 58, 533 (2020)
- Kim JH, Oh IH, Lee JH, Hong SK, Park HK, J. Korean Powder Metall. Inst., 26, 1 (2019)
- Park HK, Lee JH, Jang JH, Oh IH, J Korean J. Met. Mater., 57, 304 (2019)
- Kim HC, Ph. D. Thesis (in Korean), p.15-79, Jeonbuk University, Jeonbuk (2005).
- Kim HC, Shon IJ, Jung IK, Ko IY, Met. Mater. Int., 12, 393 (2006)
- Garcia J, Cipres VC, Blomqvist A, Kaplan B, Int. J. Refract. Met. Hard Mater., 80, 40 (2019)
- Anstis GR, Chantikul P, Lawn BR, Marshall DB, J. Am. Ceram. Soc., 64, 533 (1981)
- Shon IJ, Jeong IK, Ko IY, Doh JM, Woo KD, Ceram. Int., 35, 339 (2009)
- Almond EA, Roebuck B, Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process., 105-106, 237 (1988)