超细WC-Co复合粉的原位反应合成及烧结致密化  

Synthesis of WC-Co composite powder by reduction and carbonization reactions and its densification

作　　者：魏崇斌[1] 宋晓艳[1] 赵世贤[1] 张立[2] 刘雪梅[1] 刘文彬[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2010年第2期145-150,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(50671001);教育部新世纪优秀人才计划资助项目(NCET2006-0182);北京特色新材料产业关键技术研发攻关类项目(Z08000003220000)

摘　　要：以微米级蓝钨(WO2.9)、四氧化三钴(Co3O4)和炭黑(C)为原料,采用真空原位还原碳化反应制备超细WC-Co复合粉末,经过真空烧结得到WC-Co合金块体。利用扫描电镜、X射线衍射仪观察和分析复合粉末及合金显微形貌及物相组成,研究原料粉末中配碳量对WC-Co复合粉及合金物相与力学性能的影响。结果表明:所得平均粒径为300 nm的超细WC-Co复合粉末的主相均为WC和Co相,含有少量的η相(Co3W3C);原料粉末中配碳量(质量分数)为16.69%较为合适,此时可获得物相纯净、平均晶粒尺寸470 nm的超细晶WC-Co硬质合金,合金的横向断裂强度为2 464 MPa;原料粉末中配碳量为16.85%时,合金中存在少量的游离碳,横向断裂强度只有1 946 MPa。Using microscale tungsten oxide,cobalt oxide and carbon black as the raw materials,the ultrafine WC-Co composite powder was synthesized by reduction and carburization reactions.Then the composite powder was sintered to prepare the ultrafine-grained cemented carbides bulk by vacuum sintering.The microstructure and phases of the composite powder and the sintered bulk were investigated by scanning electron microscopy（SEM） and X-ray diffraction meter（XRD）.The effects of the carbon addition in the raw powders on the phase formation in the composite powder and on the phases and mechanical properties of the sintered bulk were investigated.The results show that the main phases of the ultrafine WC-Co composite powder are WC and Co,there is a little η（Co3W3C） phase coexisting.The raw powders with carbon black content of 16.69% is suitable.The ultrafine-grained WC-Co bulk material with pure phases and a mean grain size of 470 nm was obtained,which has the transverse rupture strength of 2 464 MPaWC-Co bulk material prepared with the raw powders containing carbon black as 16.85% has a little free carbon and the transverse rupture strength is 1 946 MPa.

关 键 词：原位还原碳化 WC-Co复合粉 超细WC-Co硬质合金 

分 类 号：TG146[一般工业技术—材料科学与工程]