Sinter-forging of a graded MMC wear component

Metal Matrix Composites (MMC) combined with the concept of Functionally Graded Materials (FGM) offer potential to adjust the material properties based on the local load conditions. In this study, a sinter-forging process was deployed to produce an MMC wear component, consisting of a steel matrix and Fused Tungsten Carbide (FTC) particles, for later use in a hot forging tool. A low alloyed carbon steel powder and a high-speed steel powder (similar to HS 6-5-2) were processed. A graded hard phase concentration was generated by stacking layers of increasing hard phase concentration (max. 10 vol.%), before the pressing of the powder specimens. After pressing, the specimens were sintered and then forged to near full density. Metallographic imaging was used to display the hard phase gradient and to identify the microstructure of the components. The dissolution of the tungsten carbides during sintering was also investigated by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX). The sinter-forged components showed a dense microstructure with embedded hard phases. The introduced gradient structure was not altered by the forging operation and the components seem promising for the planned use as a wear component in hot forming tools.