微波烧结制备纳米稀土改性WC-Co硬质合金

Fabrication of WC-Co Cemented Carbide Modificated with Nano Rare Earth by Microwave Sintering

以WC粉为基体,Co粉为粘结相,添加纳米Y2O3,通过球磨、压制成型和微波烧结制备WC-Co硬质合金。结果表明:制备的试样相结构为WC和η相(Co3W3C相),随烧结温度提高,试样的相对密度明显增大,在1 300℃时达到最高值,继续升高到1 320℃时出现局部熔融现象,随保温时间延长,试样的相对密度明显增大,但保温20 min后趋于稳定。加入纳米Y2O3可以明显细化晶粒,且其硬度和抗弯强度有一定程度提高。

WC-Co cemented carbide were prepared by ball milling, compression moulding and micro- wave sintering,with WC powder as the matrix, Co as the binding phase and addition of nano rare earth Y2O3. The results show that the phase structure of the samples are WC and η（ Co3W3C） ,the relative density of the cemented carbide increases with the sintering temperature rising, and it rea- ches maximum values at 1 300 ℃, when rising to 1 320 ℃, partial melting occurs, and the relative density of the cemented carbide increas with the holding time rising, which tends to be stable after 20 minutes. By adding nano Y2O3, the grain becomes finer, and the hardness and bending strength increase greatly respectively.