Authors: Cong Mao Mingjun Zhang Jian Zhang Kun Tang Hangyu Gan Gaofeng Zhang
Publish Date: 2015/10/30
Volume: 24, Issue: 12, Pages: 4612-4619
Abstract
Cubic boron nitride cBN particles were mixed into superfine tungsten carbide WC and then cBNWCcobalt Co composites were prepared using spark plasma sintering method The influence of the processing parameters on the microstructures and the mechanical properties of the cBNWCCo composites were investigated The results indicated that the cBN particles arranged uniformly and had an excellent adhesion with WC matrix There was no evidence of phase transformation from cBN to hBN With the increasing of the sintering temperature the liquidphase Co was increased and entered the micropores between WC and cBN particles easily Correspondingly the density the flexural strength and the hardness of the cBNWCCo composites also increased With the further increasing of the sintering temperature WC grains grew leading to the reduction of the hardness Therefore the hardness of the samples increased to a maximum value of 2978 HV at 1250 °C and then decreased with the sintering temperature The experimental results also showed that the density the flexural strength and the hardness of cBNWCCo composites increased with the holding time whereas the hardness presented a decreasing tendency when the holding time exceeded 7 min
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