蕾丝状富Co团聚组织与Co粉中硬团聚现象研究  

A Lacelike Cobalt-rich Agglomeration Microstructure and Solid Agglomeration in Cobalt Powder

作　　者：张立[1] 杨爱军 解明伟[1] 南晴[1] 冯于平[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]大连远东硬质合金有限公司,辽宁大连116043

出　　处：《硬质合金》2012年第4期208-214,220,共8页Cemented Carbides

基　　金：国家自然科学基金资助项目(51074189);国家支撑计划项目(2011BAE09B02);高等学校博士学科点专项科研基金项目(20100162110001)

摘　　要：硬质合金顶锤是WC-Co合金大制品与极端服役工况的典型代表。服役过程中硬质合金顶锤的异常失效是困扰超硬材料与硬质合金顶锤生产企业的棘手问题。本文采用扫描电镜、能谱分析以及X射线衍射分析等研究手段对硬质合金顶锤碎片与硬质合金生产用Co粉进行了观察与分析,报道了异常失效顶锤碎片微观组织结构中存在含K、Na、Ca、S、Cl、O等杂质元素、周长超过100μm的脆性蕾丝状富Co团聚组织,以及Co粉中存在因杂质与还原烧结效应导致的、外表光滑、尺度高达10μm的致密硬团聚微观缺陷。其中,富Co团聚组织中K、Na、Ca、S、Cl等杂质元素的总质量分数高达2.8%～3.45%。通过引证关联分析,认为两种缺陷之间存在一定的相关性,建议硬质合金生产企业在采购Co粉时必须重视对粉末微观质量的分析与检测。Cemented carbide anvil is a typical representative of the large WC-Co products and harsh service situa- tions. Abnormal failure of cemented carbide anvil has puzzled both the super had material and cemented carbide anvil manufacturers. Scanning electronic microscope, energy dispersive spectrometer and X-ray diffractometer were used for the analysis of typical fragments of cemented carbide anvil and cobalt powders used for the production of cemented carbide. A brittle lacelike cobalt-rich agglomeration microstructure containing impurity elements, e.g. K, Na, Ca, S, C1 and O with a perimeter over 100 I.~m in the fragment of cemented carbide anvil was observed. Solid agglomerations with smooth appear- ance and a size as large as 10 I^m in cobalt powders, caused by the combined effects of impurity elements and sintering during the reduction process were reported. The total mass fraction of impurity elements K, Na, Ca, S, Cl in the cobalt- rich agglomeration microstructure reached as high as 2.8%-3.45%. It is suggested that there exists a relationship between these two kinds of defects within the cemented carbide and the cobalt raw material; and for the cemented carbide producer, attentions should be paid on the detection of microcosmic quality in cobalt powder.

关 键 词：硬质合金顶锤 碎裂行为 蕾丝状富Co团聚组织 Co粉 微观质量缺陷 质量控制 

分 类 号：TG135.5[一般工业技术—材料科学与工程]