双层结构的梯度硬质合金的制备技术研究

Study on the Preparation Technology of Gradient Cemented Carbide with Bi-layer Structure

硬质合金中钴的梯度分布是实现功能梯度硬质合金的重要途径。通过扫描电子显微镜SEM、X射线能谱仪EDS等分析手段,研究了硬质合金原料碳量、WC晶粒和烧结温度对双层结构的硬质合金钴梯度形成以及对硬质合金硬度的影响。烧结前钴含量分别为10%和22%的原料碳量和晶粒度不同的双层合金,烧结后硬质合金形成钴梯度。烧结温度对硬质合金的钴梯度大小有明显影响,1380℃烧结1h后双层合金的钴含量梯度差5%~6%,1400℃烧结1h后双层合金的钴含量差则降低到3%梯度差。

The gradient distribution of cobalt in the cemented carbide is an important way to realize functional gradient cemented carbide.By means of the SEM and X-ray EDS,etc.,the effects of carbon content,WC grain size and sintering temperature on the formation of carbide cobalt gra-dient and the hardness of cemented carbide are studied.The bi-layer cemented carbide with different carbon contents and grain sizes of raw materials contain 10%and 22%cobalt contents before sintering,and after sintering,the cemented carbide forms cobalt gradient.The cobalt gradient in cement-ed carbide is significantly affected by the sintering temperature.After sintering for 1 hour at 1380℃,the difference of cobalt content gradient is between 5%and 6%.And at 1400℃,the cobalt content gradient difference of the bi-layer cemented carbide decreases to 3%after sintering for 1 hour.