Effects of Nano-Al2O3 Additions on Microstructures and Properties of WC-8Co Hard Metals
To investigate the role of nano-Al2O3, WC–Al2O3–8wt%Co hard metals was mixed with 0-1.2 wt% nano-Al2O3 and prepared by conventional sintering (CS) for 2 h at 1440°C to see whether the addition of Al2O3 could improve densification behaviour, the microstructure and mechanical properties of the samples. The results showed that the use of Al2O3 nanoparticles as dispersions could reduce the porosity of WC-Co alloy and decrease the relative density; it could also inhibit the growth of the grains of WC-Co hardmetal to enhance the hardness and transverse rupture strength of the alloy in a proper range. The influence of Al2O3 content on the magnetic properties including coercive force and saturated magnetic intensity of the WC–Al2O3–8wt%Co hardmetals manifested the additive of nano-Al2O3 have effect on the WC grain growth inhibition and the formation of decarbonization phase in the alloy.
Zhengyi Jiang and Chunliang Zhang
L. Sun et al., "Effects of Nano-Al2O3 Additions on Microstructures and Properties of WC-8Co Hard Metals ", Advanced Materials Research, Vols. 97-101, pp. 1649-1652, 2010