Effect of Nano–Nickel on Microstructure and Mechanical Properties of WC–6 Wt. %Co

ABSTRACT In this study, the effect of addition of up to 1 wt. % nano–nickel (n–Ni) on density, microstructure and mechanical properties of WC–6 wt. %Co was investigated. WC, Co, and n–Ni were mixed using planetary ball mill for 12 h. The powder was pressed at 150 MPa and sintered at temperatures ranging from 1350°C to 1500°C for 60 min. The density of n–Ni added WC–6Co was higher compared to bare WC–6Co when sintered at 1450°C and below. However, at 1500°C, the bare WC–6Co showed slightly higher density than n–Ni added WC–6Co. At the same sintering conditions, the WC grain size and contiguity of n–Ni added samples was lesser, and the mean Co intercept length was higher than the bare WC–6Co. Baring 1500°C sintered samples, the hardness of n–Ni added WC–6Co was higher than bare WC–6Co. The maximum Vickers hardness and transverse rupture strength (TRS) of 1748 HV 30 and 1216 MPa, respectively were achieved for 0.5 wt. % n–Ni. This is approximately 10% and 11% improvement in hardness and TRS, over bare WC–6Co. Thus, the results from the present study may provide the basis for the application of a new kind of cemented carbide based tool materials.