Microstructure and Mechanical Properties of TiB<sub>2</sub>-WC-TiC-Ni Composite Tool Materials

Abstract

TiB2-WC-TiC-Ni composite tool materials were fabricated using Ni as sintering additive by vacuum hot-pressing technique. The microstructure and mechanical properties of the composite were investigated. The composite was analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive spectrometry (EDS). The microstructure of TiB2-WC-30wt.%TiC-Ni composite containing fine WC grains, TiC grains and uniform TiB2grains. A lot of pores and coarse grains were found in TiB2-WC-10wt.%TiC-Ni composite. The pores, brittle phases and the coarse grains were harmful to the improvement of the mechanical properties of the composite. The good wettability and the adequate liquid not only inhibited the formation of the pores and the coarse grains, but also strengthened the interface energy among the grains. The flexural strength, fracture toughness and Vickers hardness of TiB2-WC-30wt.%TiC-Ni composite were 996.6±113.6MPa, 7.64±0.28MPa•m1/2and 23.58±0.82GPa, respectively.