Microwave hot press sintering: New attempt for the fabrication of Fe–Cu pre-alloyed matrix in super-hard material

Super-hard diamond drill bits were prepared with microwave hot press sintering (MHPS) method at low sintering temperature. The micro-structures were analyzed using SEM. The samples were characterized for their properties such as bending strength, hardness, relative density and compression and tensile test. The purity of the diamond in samples was investigated by Raman spectroscopy. The results display that when MHPS method is applied to the manufacture of diamond drill bits, it has prominent advantages such as shorter sintering time, lower sintering temperature et al. And the samples prepared with MHPS at 860 °C show excellent performance. The values of hardness, relative density and bending strength are 106.6 HRB, 97.6% and 895.8 MPa respectively. Thus, a reaction kinetic study was performed to analyze reaction mechanism. And a potential sintering mechanism of MHPS is discussed. This work will provide a theoretical basis for the preparation of diamond tools through MHPS process.