| Title |
Densification Behaviors of WC - Co Hard metals during Liquid Phase Sintering |
| Authors |
박종구(Jong Ku Park); 은광용(Kwang Yong Eun); 윤덕용(Duk Yong Yoon) |
| Abstract |
The liquid phase sintering behaviors of WC-Co compacts with milled and unmilled WC powders and large Co powder had been observed and compared to those observed previously in W-Ni and Fe-Cu alloys which show spherical grains. The compacts with milled WC powder show steady densification even during heating to the liquid phase sintering temperature. The compacts with unmilled WC powders show pronounced local densification during the liquid phase sintering, producing large pores. This observation is attributed to the rearrangement of the polyhedral grains under asymmetric capillary forces. In the compacts with large Co powder, large pores are initially produced when the Co particles melt and flow into the surrounding fine capillaries, but during the subsequent sintering treatment, the pores are filled by the Co-rich liquid as has been observed in W-Ni and Fe-Cu powder compacts. The mechanism of the pore filling process in WC-Co is expected to be quite complex because of the polyhedral grain shape. |