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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。
The influence of the preheating temperature on the sintering process of WC-Co system under electric field was studied by Gleeble-3500D thermal simulator. The temperature rising characteristics and shrinkage characteristics of the samples during sintering were studied. The XRD and SEM analyzes of the products were carried out. The results show that the electric field can decrease the eutectic temperature (750 ℃) of the system at higher heating rate and the unbalanced reaction occurs during the sintering process. The mesophases of CO3W3C and CO6W6C are formed. With the increase of heating rate High and intermediate phases gradually change and decompose; In addition, the preset temperature rate affects the amount and distribution of the liquid phase quantity of the system, and the temperature rises at the rate of 50 ℃ / s, the liquid phase is moderate and the distribution is even. The reaction product WC With the increase of heating rate, the average size of particles decreased to some extent, but both were much smaller than the average size of particles after vacuum sintering.