中文摘要：

采用Gleeble-3500D热模拟机研究预设升温速度对WC-Co体系在电场作用下烧结过程的影响。研究了试样在烧结过程中的升温特点和收缩特性,结合对产物的X射线衍射分析（XRD）以及扫描电镜（SEM）等的分析。结果表明,在较高的升温速度下,电场作用可降低体系的共晶反应温度（750℃）;烧结过程中出现了不平衡反应,生成了CO3W3C,CO6W6C的中间相,随着升温速度的升高,中间相逐渐转变和分解;此外,预设升温速度的高低影响了体系液相量的多少和分布,以50℃/s的升温速度升温,液相产生适中且分布较均匀;反应产物WC颗粒的平均尺寸随着升温速度的增加,发生了不同程度得减小,但均远远小于传统真空烧结后颗粒的平均尺寸。

英文摘要：

Using Gleeble-3500D thermal simulation instrument,the effect of heating rate on sintering process of WC-Co system was investigated.Characteristics of heating and shrinkage during the sintering process were examined.Microstructure of the products was analyzed by means of XRD and SEM.The results show that the eutectic temperature of WC-Co system （750 ℃ ） decreases under electric field.Unbalanced reaction takes place causing the formation of intermediate phases Co3 W3 C,Co6 W6 C,which decompose with increasing heating rate.Moreover,depending on the heating rate different distribution and amount of liquid phase present during the sintering process.Especially,at heating rate of 50 ℃ /s,moderate amount of liquid phase forms and distributes uniformly in the sintering products.At the same time,as heating rate increases,the particle size of sintering products decreases.However,the particle size of sintering products by this method is far smaller than those produced by traditional method.