Study on Microstructure and Mechanical Properties of WC-10Ni(3)Al Cemented Carbide Prepared by Different Ball-Milling Suspension

In this paper, WC-10Ni(3)Al cemented carbides were prepared by the powder metallurgy method, and the effects of ball-milling powders with two different organic solvents on the microstructure and mechanical properties of cemented carbides were studied. We show that the oxygen in the organic solvent can be absorbed into the mixed powders by ball-milling when ethanol (CH(3)CH(2)OH) is used as a ball-milling suspension. This oxygen leads to the formation of α-Al(2)O(3) during sintering, which improves the fracture toughness, due to crack deflection and bridging, while the formation of η-phase (Ni(3)W(3)C) inhibits the grain growth and increases the hardness. Alternatively, samples milled using cyclohexane (C(6)H(12)) showed grain growth during processing, which led to a decrease in hardness. Therefore, the increase of oxygen content from using organic solvents during milling improves the properties of WC-Ni(3)Al composites. The growth of WC grains can be inhibited and the hardness can be improved without loss of toughness by self-generating α-Al(2)O(3) and η-phase (Ni(3)W(3)C).