放电等离子烧结不同粒径匹配的WC-Co混合粉末  

Spark plasma sintering WC-Co mixed powders of various grain size matching

作　　者：赵世贤[1] 宋晓艳[1] 魏崇斌[1] 刘雪梅[1] 张久兴[1] 

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

出　　处：《粉末冶金材料科学与工程》2010年第1期32-37,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;50871001);教育部新世纪优秀人才项目(NCET2006);教育部博士点基金资助项目(20070005010);北京特色新材料产业关键技术研发攻关类项目(Z08000003220000)

摘　　要：采用一种包括混合粉末真空预处理和放电等离子烧结(SPS)的新型烧结技术,制备超细晶WC-10Co硬质合金块体。采用场发射扫描电镜观察硬质合金的形貌和晶粒组织,采用三点弯曲法测量试样的断裂强度,利用显微硬度仪测量维氏硬度HV30且据此估算试样的断裂韧性KIC,并与真空烧结和直接SPS试样进行对比,同时还研究初始粉末中WC粉与Co粉的粒径匹配对SPS块体的显微组织和力学性能的影响。结果表明,与真空烧结和直接SPS相比,此种方法制备的WC-10Co合金晶粒细小、组织均匀,具有优异的综合力学性能,尤其是强度明显提高,硬度为1608HV30,断裂韧性为14.0MPa.m1/2,横向断裂强度为3100MPa;WC和Co粉末的粒径匹配对SPS块体的显微组织和力学性能具有较显著的影响。The ultrafine WC-10Co cemented carbide were prepared by a new method that contains pretreatment of the powder mixture and subsequent consolidation by spark plasma sintering （SPS）. The microstructure and properties of the prepared cemented carbide were studied by scanning microscope,VICKERS diamond hardometer,mechanical properties measuring device,etc,and comparing the results with that of vacuum sintered and direct SPSed samples. As compared with the vacuum sintered and direct SPSed samples,the WC-10Co cemented carbide prepared by the direct SPS consolidation method has finer grains,homogeneous microstructure and higher mechanical properties including the hardness of 1 608 HV30,fracture toughness of 14.0 MPa.m1/2 and transvere rapture strength of 3 100 MPa. Mean while,the effect of the grain size matching between raw WC powder and Co powder on the microstructure and mechanical properties of the pretreated and then SPSed compact was also studied,which shows that particle-size combination has great effects on the microstructure and mechanical properties of the cemented carbide.

关 键 词：超细晶硬质合金 粒径匹配 放电等离子烧结 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]