高能球磨热压烧结制备定向排布板状WC硬质合金

Preparation of oriented plate-like WC grains in cemented carbides by high-energy ball milling and special hot-pressing sintering

采用高能球磨辅助特殊的热压烧结工艺制取定向排布板状WC硬质合金,研究了烧结温度和球磨时间对板状WC晶粒形成及其定向排布的影响。研究结果表明:烧结温度越高,越有利于晶粒粗化,形成大块板状WC晶粒;高能球磨中引入的缺陷是促进WC晶粒长径比提高的主要原因;WC晶粒的均匀性、粒径和长径比是影响其定向排布的主要因素。制备定向排布板状WC硬质合金是同时提高硬质合金硬度和韧性的有效方法。

Oriented plate-like WC grains in cemented carbides were prepared by high-energy ball milling and special hot-pressing sintering. At the same time, the effects of sintering temperature and milling time on the formation and orientation of plate-like WC grains were studied. The results show that high sintering temperature favors the formation of large plate-like WC grains. The aspect ratio of WC grains will be increased because of the defects introduced by high-energy ball milling. The uniformity, size and aspect ratio of WC grains are the main factors to control the orientation. The mechanical property of this new cemented carbide indicates that the preparation of oriented plate-like WC grains in cemented carbides is another valid method to increase both the hardness and fracture toughness.