471和3555两种硬质合金的高温氧化行为  

High temperature oxidation behavior of 471 and 3555 cemented carbides

作　　者：黄道远[1] 易丹青[2] 李劼[1] 王万林[1] 

机构地区：[1]中南大学冶金科学与工程学院,湖南长沙410083 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《材料热处理学报》2013年第2期27-31,共5页Transactions of Materials and Heat Treatment

摘　　要：对471和3555两种硬质合金进行高温氧化试验,使用扫描电镜对氧化层组织进行观察,并对其氧化过程进行热力学和动力学分析。结果表明:硬质合金氧化时,粘结相比硬质相优先发生氧化。氧化后471合金晶粒由规则多边形状变为柱状,而3555合金氧化层外层组织呈柱状,内层氧化物为层状。两种合金的氧化速度都随氧化温度升高而急剧上升,471合金氧化增重曲线几乎为直线,其氧化反应激活能254.7 kJ.mol-1,3555合金氧化增重符合抛物线规律,氧化激活能大小为336.7 kJ.mol-1。Abstract：High temperature oxidation treatment was performed on 471 and 3555 cemented carbides. The microstructure of oxidized layer was observed by scanning electron microscopy. Oxidation process was analyzed by thermodynamics and kinetics. The results show that binder phase is oxidized firstly and then oxidation of hard phase oeours. After oxidation the grain shape of 471 alloy changes from the polygonal to columnar. The outer layer microstructure of 3555 alloy shows columnar and the inner shows lamellar. The oxidation rate of two alloys increases rapidly with the increasing temperature. The linear oxidation kinetics curves of 471 alloy is observed, which shows poor oxidation resistance and the oxidation activation energy is 254.7 kJ· mol^-1, while the oxidation kinetics of 3555 alloy obeys a parabolic rule, and the oxidation activation energy of 3555 alloy is 336.7 kJ·mol^-1.

关 键 词：硬质合金 氧化 微观组织 激活能 

分 类 号：TG135.5[一般工业技术—材料科学与工程]