The Effects of Powder Composition on Microstructure and Properties of Hot-Pressed Matrix Materials for Sintered Diamond Tools

The main objective of this investigation was to determine the effects of powder composition on microstructure and properties of iron-base materials used as matrices in sintered metal–diamond composites. Ball-milled Fe-Ni-Cu-Sn-C, Fe-Ni-Cu-Sn-C-Al2O3 and Fe-Ni-Cu-Sn-C-Al4C3 powders were tested. The powders were consolidated a virtually pore-free condition by the hot press route. Irrespective of their chemical composition, they were held for 3 min at 900 °C and 25 MPa. The as-sintered (micro-)structures were examined by scanning electron microscopy (SEM) and x-ray diffraction (XRD). All materials showed fine-grained microstructures and significant strengthening due to a martensitic transformation.