微波烧结法制备WC-10Co硬质合金

Preparation of WC-10Co cemented carbide by microwave sintering

以直接还原碳化方法制备的超细碳化钨-钴复合粉末为原料,采用微波烧结、放电等离子体烧结、真空烧结制备碳化钨-钴硬质合金,研究1 200℃的烧结温度下,不同烧结方法对碳化钨-钴硬质合金性能的影响。微波烧结超细WC-10Co复合粉末,在1 200℃的烧结温度下保温7 min,制备了综合性能优良的超细WC-10Co硬质合金,相对密度达到99.5%,洛氏硬度为HRA 92.5,矫顽力为30.0 kA/m,磁饱和度为83%,平均晶粒粒度≤350 nm。与采用常规烧结方法得到烧结体相比,烧结时间显著减少,烧结体性能提高;与放电等离子体烧结相比,晶粒异常长大得到一定的控制。

Ultrafine WC-10Co powder prepared by a direct reduction and carbonization process was used to prepare the WC-10Co cemented carbide, and the properties of WC-10Co cemented carbide prepared by microwave sintering, spark plasma sintering or vacuum sintering at 1 200 ℃ were compared. The relative density of microwave sintered ultrafine WC-10Co cemented carbide reaches 99.5%, and magnetic coercivity is more than 30.0 kA/m, Rockwell A hardness is more than 92.5, average grain size is less than 350 nm, and ultrafine cemented carbide with excellent properties is obtained. Compared with sintering body sintered by conventional sintering, the microwave sintering can not only lower sintering time, but also increase the properties of cemented carbide, and the discontinuous grain growth is inhibited effectively by microwave sintering process compared with spark plasma sintering process.