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.
出处
《电子显微学报》
CAS
CSCD
北大核心
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)~~
