热压和放电等离子烧结对硬质合金材料微观组织和性能的影响  

Characterization of cemented carbides prepared by hot pressing and spark plasma sintering

作　　者：刘雪梅[1] 宋晓艳[1] 刘文彬[1] 赵世贤[1] 张久兴[1] 殷福星 

机构地区：[1]北京工业大学材料学院,新型功能材料教育部重点实验室,北京100124 [2]日本国立材料科学研究所,日本筑波305-0047

出　　处：《电子显微学报》2009年第1期1-5,共5页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.50401001 ,No.50671001)~~

摘　　要：本文采用XRD、EBSD等测试手段,对热压(HP)和放电等离子烧结(SPS)获得的硬质合金材料的相成分、微观组织及其性能进行了比较,并对其形成原因进行分析。结果表明,两种烧结方法获得的试样均具有高的致密度及纯净的WC和Co相,试样内晶粒没有择优取向;绕[1010]轴取向角为90°的WC-WC晶界为低能晶界,因此该种晶界大量存在且均匀分布于试样中;两种烧结方法获得试样硬度基本一致;但SPS技术因加热速率快、保温时间短,有效阻止了WC晶粒的长大,特别是高温烧结阶段的晶粒粗化,因此获得的晶粒尺寸小于热压烧结试样,从而具有高的断裂韧性。由此表明快速合成的放电等离子烧结技术有利于超细晶和纳米晶硬质合金材料的制备。The phase constitution, mierostructure and properties of the cemented carbides prepared by hot pressing and spark plasma sintefing techniques were characterized and compared. The high density and the pure phase constitution were obtained by both the sintefing methods. The misofientation distribution function （MDF） shows a preferred misorientation relationship of WC-WC grain boundaries as 90° with respect to the [ 10 70] direction. These grain boundaries are the low-energy boundaries in the material. The two samples have nearly the same hardness. The grain size in the SPSed sample is smaller than that in the hot-pressed sample, which shows the advantages of SPS technique in rapid heating rate and short holding time and thus inhibits grain coarsening during the sintering process, especially the grain growth at high temperatures.

关 键 词：热压烧结 放电等离子烧结 EBSD WC-CO硬质合金 

分 类 号：TG132.1[一般工业技术—材料科学与工程]