Microstructure and properties of ultrafine cemented carbides—Differences in spark plasma sintering and sinter-HIP

The spark plasma sintering (SPS) and hot isostatic pressing (sinter-HIP) were taken as the representative methods of rapid sintering and liquid-state sintering technologies, respectively, to fabricate the WC–Co cemented carbides. The microstructures and properties of the bulk materials prepared by the two techniques were characterized and compared systematically. It was demonstrated that the big difference in mechanical properties of the cemented carbides prepared by SPS and sinter-HIP depends on the configuration of WC and Co phases and the WC/Co orientation relationship, which result from the intrinsic features of the sintering technologies. The mechanisms for the excellent properties obtained in the cemented carbides prepared by sinter-HIP were proposed, based on which the favorable microstructures and optimized processing methods concerning liquid-state sintering may be developed.

► Representative methods of rapid sintering and liquid-state sintering.
► Big difference in mechanical properties of two kinds of samples.
► Mechanism related to configuration and orientation relationship of WC and Co phases.
► Intrinsic features of sintering technologies and their effects.