Cu部分代Co超细硬质合金研究

Effect of the Partial Substitution of Co by Cu on the Properties of Ultrafine Cemented Carbide

基于Cu与Co相同的晶型结构和相似的原子结构,采用共沉淀方法,制备Cu部分代Co的WC-10Co硬质合金,研究Cu对材料的组织和力学性能的影响.实验结果表明,通过Cu-Co共沉淀方式将Cu加入粘接相中,形成Co(Cu)固溶体,在液相烧结过程中Cu均匀地分布在Co中,可以降低WC在粘接相中的溶解度,有效阻碍WC颗粒的溶解再析出,抑制WC晶粒的长大,提高硬质合金的硬度。Cu的添加还可以使粘结相产生固溶强化,提高硬质合金的抗弯强度。当Cu的质量添加量为1.5%时,硬质合金综合力学性能得到提高,合金硬度由无Cu时的HRA92.6提高至HRA93.2,抗弯强度由2150 MPa提高至2490 MPa.

Based on the same crystal structure and atomic structure of Cu and Co, coprecipitation method was taken to fabricate the ultrafine cemented carbide with Cu partly instead of Co. The effect of Cu on the properties of WC-10Co cemented carbide was investigated. The results show that with the addition of Cu by coprecipitation method, the Co（Cu） solid solution forms, and since Cu can distribute uniformly in WC-10Co during sintering,, the solubility of WC in binding phase decreases, the re-precipitation of dissolved WC particles can be hindered effectively, which results in the repression of WC grains growth, and the hardness of cemented carbide increases. The addition of element Cu can also play a role in solid solution strengthening of binding phase improving the transverse rupture strength of cemented carbide. When the Cu content is 1.5 wt%, cemented carbide can obtain the best mechanical properties with the hardness increasing from HRACJ2.6 to HRA 993.2 and the transverse rupture strength increasing from 24990 MPa to 2150 MPa.