Oluwatosin Job Ojo-kupoluyi, Suraya Mohd Tahir, Azmah Hanim Mohamed Ariff, B. T. Hang Tuah Baharudin, Khamirul Amin Matori, Mohd Shamsul Anuar
November 25, 2017
Manufacturing tailored materials is commonly faced with the challenge of shrinkage mismatch between layers resulting in delamination. The effects of sintering temperature and carbon variation on the densification and interfacial bond strength of bilayer cemented tungsten carbide and steel processed through powder metallurgy are analyzed. It is revealed through field-emission scanning electron microscopy images that inter-layer diffusion induced by liquid-phase sintering plays a major role in the densification and bonding of layers. Through dimensional analysis of sintered bilayer specimens, the strain rate of cemented tungsten carbide is observed to surpass that of steel. An enhanced densification rate of 6.1 % and M 6 C (eta carbide) reduction with increased carbon level results in strong interfacial bonding in specimens sintered at 1 280 °C. At 1 295 °C, diffusion accelerates and the axial and radial shrinkage increase by 14.05 % and 13.35 %, respectively, in 93.8 wt.% WC – 6 wt.% Fe – 0.2 wt.% C and 93.2 wt.% Fe – 6 wt.% WC – 0.8 wt.% C, thereby increasing the tendency for complete delamination.