Investigation into the sintered behavior and properties of nanostructured WC–Co–Ni–Fe hard metal alloys

Nanomaterials normally possess high strength, high hardness and excellent ductility and toughness. In the research, various vacuum sintering temperatures (1250 °C, 1300 °C, 1350 °C and 1400 °C) were explored in order to investigate the optimal parameters of micro- and nano-WC sintered composites; and further to compare the sintered behavior and properties of two different sizes of WC materials. All specimens were fabricated by using vacuum sintering of the powder metallurgy technique. The experimental results show that micro- and nano-WC specimens generated a good liquid-phase sintering at 1350 °C sintered for 1 h, and thus, exhibited excellent mechanical properties. The porosities were decreased to 0.36% and 0.8%, the hardness was enhanced to 90.1 and 91.4 HRA and the TRS was increased to 1441.62 and 1540.56 MPa, respectively. Since there is an effect upon the grain refinement, nano-WC obviously possesses better performance than the micro-WC hard metal alloys. Meanwhile, the KIC value for sintered nano-WC dramatically increased to 12.71 MPa m1/2.