Sintering of WC-10%Co nano powders containing TaC and
VC grain growth inhibitors
VC grain growth inhibitors
(1. Department of Material Science, Saveh Branch, Islamic Azad University, P.O.Box 39187366, Saveh, Iran;
2. Department of Material Engineering, Maham Science and Technology Center,
P.O.Box 1668918479, Tehran, Iran;
3. Department of Material Science, Iranian Research Organization for Science and Technology,
P.O.Box 15815/3538, Tehran, Iran)
2. Department of Material Engineering, Maham Science and Technology Center,
P.O.Box 1668918479, Tehran, Iran;
3. Department of Material Science, Iranian Research Organization for Science and Technology,
P.O.Box 15815/3538, Tehran, Iran)
Abstract: WC-10%Co (mass fraction) nanocomposite was synthesized by high energy planetary ball milling at balls to powder mass ratio of 15. For inhibition of growth of WC grains during sintering, TaC and VC were used as inhibitors. Hardness and fracture toughness results reveal that the addition of TaC increases the toughness of hard metal and VC increases the hardness of the sample due to the effective reduction of WC grain size. The effect of co-addition of 0.6% TaC and 0.7% VC on physical and mechanical properties of WC-10%Co sintered sample was investigated. The hardness of the sample is increased to HV30 1 787, which is 24% more than that of the inhibitor-free sample; the fracture toughness achieves 8.7 MPa∙m1/2, 35% higer then that of the inhibitor-free sample; the grain growth is inhibited and grain size achieves 0.38 μm.
Key words: WC-10%Co; TaC; VC; inhibitor; cemented carbides