(1. 中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083；2. 長(zhǎng)沙礦冶研究院有限責(zé)任公司，長(zhǎng)沙 410012)
摘 要: 利用特粗晶與超粗晶硬質(zhì)合金粗大粘結(jié)相平均自由程以及粗大WC原料粉末的特性，研究單一Cr、V以及Cr-RE與V-RE添加劑對(duì)特粗晶與超粗晶WC-Co合金微觀組織結(jié)構(gòu)、物理力學(xué)性能以及合金中Co粘結(jié)相納米壓痕力學(xué)性能的影響。結(jié)果表明，在此合金體系，Cr的加入可使合金保持微觀組織結(jié)構(gòu)均勻、WC晶粒粗大以及高韌性的特性，而且可使Co粘結(jié)相納米壓痕硬度HV2 mN提升了20.5%；V的加入使合金中WC晶粒大小出現(xiàn)明顯兩極分化，并顯著降低合金韌性；微量混合稀土(RE)對(duì)V和Cr在合金中的作用行為影響不顯著；合金矯頑磁力、硬度以及Co粘結(jié)相彈性模量對(duì)合金成分變化不敏感。
關(guān)鍵字: 特粗晶硬質(zhì)合金；添加劑；鈷粘結(jié)相；納米壓痕；微觀組織
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Changsha Mining and Metallurgy Research Institute Co., Ltd., Changsha 410012, China）
Abstract:Taking the advantage of the large mean free path of the binder phase and the coarse WC raw material, the behaviors of Cr, V, Cr-RE and V-RE additives in super extra coarse and extra coarse WC-Co alloys were investigated. It included the microstructure, physical and mechanical properties of the alloys and the nano indentation mechanical properties of the cobalt binder phase. The results show that in these alloy systems, the alloys with Cr additive are characterized with homogeneous microstructure, super extra coarse WC grain size and high toughness. With the independent addition of Cr, the nano indentation hardness HV2mN of the cobalt binder phase of the alloy can be increased by 20.5%. The addition of V can result in the polarization of the WC grain sizes and the substantial decrease in toughness. The effect of RE (mischmetal) in small amount on the behavior of Cr, V in the alloys is insignificant. The magnetic coercivity and hardness of the alloys as well as the elastic modulus of the cobalt binders are insensitive to the composition of the alloys.
Key words: super extra coarse cemented carbide; additive; cobalt binder phase; nano indentation; microstructure
