| Title |
Fabrication and Mechanical Properties of WC Alloy Hard Materials by a Pulsed Current Activated Sintering Method |
| Authors |
이정한(Jeong-han Lee); 박현국(Hyun-kuk Park); 장준호(Jun-ho Jang); 홍성길(Sung-kil Hong); 오익현(Ik-hyun Oh) |
| DOI |
https://doi.org/10.3365/KJMM.2017.55.11.783 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
pulsed current activated sintering process; rapid sintering; WC-.Co; planetary ball milling; mechanical property |
| Abstract |
In this study, planetary ball milled WC-5 wt%Co powders were sintered using the pulsed current activated sintering (PCAS) process. With this process, fully densified hard materials were obtained in a shorter time than conventional processes such as a HP and HIP. The particle sizes of the planetary ball milled WC and Co were 0.114 μm and 0.154 μm, respectively. The PCAS process was performed at temperatures up to 1300 ℃ with 60 MPa and electric current for 13 min without any significant change in the grain size. The WC-5 wt% Co hard materials were fully densified with a relative density of up to 99.8%. The density of WC-5 wt% Co hard materials increased with increasing shrinkage ratio. In addition, the Co particles penetrated into the WC particles by dissolving and re-precipitation, and finally hard materials were completely densified. The average grain size of the WC-5 wt%Co was 0.25 μm, and the hardness and fracture toughness were 2,386 kg/mm2 and 6.0 MPa·m1/2, respectively. The mechanical properties of the WC-5 wt% Co hard materials were excellent because of grain refinement and densification.(Received June 9, 2017; Accepted July 12, 2017) |