Rapid sintering of ultra fine WC and WC-Co hard materials by high-frequency induction heated sintering and their mechanical properties

Abstract

Using a high-frequency induction heated sintering (HFIHS) method, the densification of binderless WC and WC-x wt.%Co (x=8, 10, 12) hard materials were accomplished using an ultra fine powder of WC and WC-Co. The advantages of this process are that it allows very quick densification close to the theoretical density and prohibits grain growth in nano-structured materials. Nearly fully dense WC and WC-Co with a relative density of up to 99.9% could be obtained with a simultaneous application of 60 MPa pressure and induced current (within 2 min) without a significant change in grain size. The average grain size of WC was approximately 270 nm for WC-x wt.%Co. The hardness and fracture toughness of the dense WC and WC-Co composites produced by HFIHS were investigated.