原料形貌特性和高温梯度碳化工艺对纳米WC粉末及其WC-Co合金均匀性的影响  

Effects of the Morphology of Tungsten Oxide Powders and High Temperature Gradient Carbonization Process on the Homogeneity of Nanometer WC and its WC-Co Alloys

作　　者：鄢志刚 雷纯鹏 蔡海燕 吴爱华 唐建成[3] Zhigang Yan;Chunpeng Lei;Haiyan Cai;Aihua Wu;Jiancheng Tang(Jiangxi Jiangwu Cemented Carbide Company,Jingan Jiangxi 330699,China;Nanchang Cemented Carbide Liability Company,Nanchang Jiangxi 330013,China;School of Materials Science and Engineering,Nanchang University,Nanchang Jiangxi 330031,China)

机构地区：[1]江西江钨硬质合金有限公司,江西靖安330699 [2]南昌硬质合金有限责任公司,江西南昌330013 [3]南昌大学材料科学与工程学院,江西南昌330031

出　　处：《硬质合金》2021年第4期255-263,共9页Cemented Carbides

基　　金：国家自然科学基金《碳辅助氢还原制备纳米钨粉的机理及其在纳米碳化钨粉和纳米晶WC-Co硬质合金中的应用》(51364036);南昌硬质合金有限责任公司校企合作成果产业化应用项目。

摘　　要：采用不同氧化钨原料,通过氢还原、高温碳化工艺制备纳米W、WC粉末,研究了氧化钨形貌特性对纳米W、WC粉体形貌、均匀性的影响。择优选取了高比表面特制蓝钨(SBTO),并结合新型高温梯度碳化工艺制备了纳米碳化钨粉末,研究了新型高温梯度碳化工艺对纳米WC粉体特性及超细晶WC-Co硬质合金性能的影响。通过比表面测定仪、费氏粒度仪、定碳仪测定了粉体的比表面、粒度、总碳等,用扫描电镜(SEM)观察了粉末的形貌和合金的显微组织,同时按WC-Co硬质合金相关测试标准对烧结试样的性能进行了检测、分析。结果表明,颗粒均匀、比表面积大,具有疏松、多空隙形貌结构的氧化钨粉末,利于制备出颗粒均匀、分散性好的纳米W粉和WC粉;晶粒聚集和异常粗大颗粒的产生,与碳化过程中团聚纳米钨粉颗粒因烧结合并增粗有关,而高温梯度碳化能有效抑制此类现象的发生;采用特制蓝钨(SBTO)和高温梯度碳化工艺的良好结合,可以制备出具有均匀组织结构的高性能超细晶WC-Co硬质合金。Nanometer tungsten and tungsten carbide powders are respectively prepared by the typical hydrogen reduction and high temperature carbonization process using different tungsten oxide powders as raw materials.Effects of the morphology of different tungsten oxide powders on the homogeneity and morphology of the nanometer tungsten and tungsten carbide powders are characterized.Nanometer tungsten carbide powders are prepared also by the new high temperature gradient carbonization process using special blue tungsten oxide(SBTO)with the high specific surface area and uniform particle size.The effects of the new carbonization process on the homogeneity and morphology of nanometer tungsten carbide powders and its sintered alloys are studied.The particle size and specific surface area of different powders are measured by Fisher sizer and Specific surface equipment,the total carbon of different powders were analyzed by carbon analyzer,the morphology of powders and micro-structures of WC-Co sintered alloys are observed by scanning electronic microscope(SEM).In addition,the physical and mechanical properties of WC-Co sintered alloys are tested and analyzed according to related cemented carbide performance testing standard.The results shown that the tungsten oxide powder with the morphological characters such as uniform particle size,high specific surface area,loose and porous structure are advantage to prepare the high quality nanometer tungsten and tungsten carbide powders with the characters of homogeneous structure and good dispersion.The occurrence of the grain aggregation and abnormal coarse grains of nanometer WC powder is mainly result from the burning binding of agglomeration particle of nanometer tungsten powder during carbonization process.However,the new high temperature gradient carbonization process can effectively inhibit the occurrence of such phenomena.As a result,the high performance ultra-fine WC-Co alloy with homogeneous structure are produced by the new high temperature gradient carbonization process using

关 键 词：形貌 纳米WC 高温梯度碳化 WC-CO合金 均匀性 

分 类 号：TG135.5[一般工业技术—材料科学与工程]