硬质合金渗硼层组织及厚度的研究

本文以WC-Co硬质合金为渗硼研究对象,研究开发出一种感应加热密闭容器气-固渗硼工艺方法 ,借助于金相显微镜对渗硼层厚度实现了直接观察,应用SEM、EDS能谱、XRD、场发射电镜等对合金的组织进行了分析。实验结果表明:渗硼层厚度可达0.1～0.5 mm,渗硼层Co粘结相中弥散分布羽毛状W-C-Co-B析出相;感应加热、密闭容器中气相的作用和渗硼剂中的稀土促进了渗硼过程的进行;硬质合金Co含量、渗硼温度、渗硼时间增加有利于渗硼层厚度增加;应用数据拟合得到了YG11合金渗硼层厚度与渗硼温度、渗硼时间关系表达式。

Investigation on Microstructure and Thickness of Boronizing Layer in Cemented Carbide

The boronizing technology characterized with induction-heating and boronizing agents in gas-solid state had been applied to the treatment of WC-Co alloy in a sealed container.The thickness of the boronizing layer was observed by metallographic microscope,and the microstructure of the boronized alloy was analyzed by SEM,EDS,XRD and FESEM.Experimental results show that the thickness of the boronizing layer is up to 0.1～0.5 mm and W-C-Co-B feather-shaped precipitates are dispersed in Co binder phase.Induction-heating and gas-phase and rare-earth element in the boronizing agent in the sealed container promote boronization.The boronizing thickness increases with the increase of Co content in the alloy,the boronizing temperature and boronizing time.The boronizing thickness of YG11 alloy has been formulated with boronizing temperature and time by means of data fitting.