以石墨烯为碳源的硬质合金制备与性能  

Preparation and Mechanical Properties of Hard Metals Using Graphene as Carbon Source

作　　者：王西龙[1] 宋晓艳[1] 张哲旭[2] 刘雪梅[1] 刘兴伟[1] 杨诚[2] 李玉玺 

机构地区：[1]北京工业大学新型功能材料教育部重点实验室,北京100124 [2]清华大学深圳研究生院,广东深圳518055 [3]自贡长城硬面材料有限公司,四川自贡643000

出　　处：《稀有金属材料与工程》2016年第12期3262-3266,共5页Rare Metal Materials and Engineering

基　　金：国家高技术研究发展计划("863"计划)主题项目(SS2013AA031401);国家自然科学基金(51174009);北京市自然科学基金重点项目(2131001);北京市"长城学者"计划项目(CIT&TCD20130314)

摘　　要：以N-甲基吡咯烷酮分散的石墨烯代替常规的冶金炭黑作为碳源,采用短流程原位还原碳化反应制备出纳米晶WC-Co复合粉末。采用放电等离子烧结系统对复合粉末进行快速烧结致密化。结果表明,石墨烯作为碳源可显著降低原位还原碳化反应温度,复合粉末粒径细小且分布均匀。得到的超细晶硬质合金块体材料平均晶粒尺寸约为290 nm,HV_(30)硬度值为13.877±0.131 GPa,断裂韧性KIC值为8.3±0.1 MPa·m^(1/2)。通过HRTEM观测表明,试样中WC/WC晶界、WC/Co相界、WC/C相界具有很高的匹配度。Normal carbon source black carbon was substituted by graphene which was dispersed in N-Methyl-2-pyrrolidone and nanocrystalline WC-Co composite powders were prepared using a short process in-situ reduction and carbonization reaction method. The results show that graphene as the carbon source could decrease the reaction temperature, and the particles of WC-Co composite powders are fine and the particle size distributes uniformly. Composite powders were consolidated through the spark plasma sintering system and the mean grain size of WC in WC-Co cemented carbides is about 290 nm. Vickers hardness and fracture toughness of the bulk is 13.877±0.131 GPa and 8.3±0.1 MPa·m^1/2, respectively. HRTEM images show that the grain boundaries of interfaces between WC/WC, WC/Co and WC/C are of low misfit.

关 键 词：硬质合金 原位还原碳化反应 放电等离子烧结 力学性能 微观组织 

分 类 号：TG135.5[一般工业技术—材料科学与工程]