Investigation of Mechanical Properties and Microstructure of WC-10%Wtco Containing Tac Grain Growth Inhibitor

Tungsten carbide-10wt% cobalt powders with particle size of 0/5micron were milled by high energy planetary ball mill at different balls to powder weight ratios (BPRs). The powders characterizations were studied by SEM، TEM and XRD. The best results were found at BPR equal to 15. In this ratio، the crystallite and particle size of WC decreased to 39 nm. In order to reduce the WC grain growth during the sintering process، tantalum carbide was added as a WC grain growth inhibitor during sintering. The prepared powders were compacted at 200 MPa and sintered at 1370-1450 ˚C during 1 hour. Then the mechanical and micro structural properties of the samples were determined. At optimum sintering temperature، the inhibition of WC grains growth is improved and the hardness increases from 1490 to 1615 HV30.