Fabrication of WC-Ni-Si-B4C Composite and Diffusion Bonding with Stainless Steel

The effects of Ni on the mechanical properties of WC-Xwt.%Ni-1.5wt.%Si-1.1wt.%$B_4C$ composite (X = 21.6, 23.6, 25.6 and 27.6 wt.%) were investigated in order to replace Co with Ni as the binder metal for hard materials based on WC-Co system. Using X-ray diffraction, optical microscopy, field-emission scanning electron microscopy results, the microstructure, pore distribution and grain size of the composites sintered at $1,150^{\circ}C$ were examined with different fraction (X = 21.6, 23.6, 25.6 and 27.6 wt.%) of binder metal Ni. The average WC grain size of the $WC-Ni-Si-B_4C$ composites was about $1{\mu}m$. The Rockwell hardness : A (HRA) and transverse rupture strength were about 88HRA and $110kgf/mm^2$, respectively. The obtained sample was bonded with SM45C at a temperature of $1,050^{\circ}C$. The thickness and mechanical properties of the bonded area were investigated with different dwell time at a bonding temperature of $1,050^{\circ}C$.

WC-Ni-Si-B4C계 초경합금 제조 및 스테인레스 스틸과의 확산접합