摘要
通过富氮气氛烧结WC‒10TiC‒0.5VC‒0.5Cr_(2)C_(3)‒12Co和WC‒12Co硬质合金,研究梯度结构和均匀结构硬质合金的微观结构及力学性能。利用扫描电子显微镜观察合金断面的微观形貌,使用X射线衍射仪和能谱仪分析合金物相组成,并对合金表面和芯部的硬度与断裂韧性进行测试。结果表明:与均匀结构的WC‒12Co硬质合金不同,WC‒10TiC‒0.5VC‒0.5Cr_(2)C_(3)‒12Co梯度结构硬质合金的表层富含立方相TiCN,该表层的厚度大约为12μm,表层下方是富钴粗晶过渡层。WC‒10TiC‒0.5VC‒0.5Cr_(2)C_(3)‒12Co硬质合金具有表面硬度高、芯部断裂韧性高、WC晶粒细小及分布均匀等优点。
The microstructure and mechanical properties of the WC‒10TiC‒0.5VC‒0.5Cr_(2)C_(3)‒12Co and WC‒12Co cemented carbides in the functionally graded and uniform structure were systematically investigated by sintering in nitrogen-rich atmosphere.The scanning electron microscope(SEM),energy disperse spectroscope(EDS),and X-ray diffractometer(XRD)were used for the microstructure observation and phase composition analysis,and the hardness and fracture toughness tests were made in both the surface and the center of the cemented carbides.The results show that,different from the WC‒12Co cemented carbides in uniform structure,the surface layer of the WC‒10TiC‒0.5VC‒0.5Cr_(2)C_(3)‒12Co cemented carbides in the gradient structure is rich in TiCN cubic phase,which is about 12μm in thickness,and there is a cobalt-rich and coarse-grain intermediate layer below the surface layer of the WC‒10TiC‒0.5VC‒0.5Cr_(2)C_(3)‒12Co cemented carbides.Such gradient and ultrafine cemented carbides show the advantage as the high hardness in the surface layer,the high fracture toughness in the core,and the ultrafine and uniform WC grain.
作者
陈健
黄怿平
朱睿
周莉
邓欣
伍尚华
刘炳耀
CHEN Jian;HUANG Yi-ping;ZHU Rui;ZHOU Li;DENG Xin;WU Shang-hua;LIU Bing-yao(School of Mechatronic Engineering,Guangdong Polytechnic Normal University,Guangzhou 510635,China;Master Group(Guangdong)Technology Research Co.,Ltd.,Yunfu 527400,China;School of Electromechanical Engineering,Guangdong University of Technology,Guangzhou 510006,China)
出处
《粉末冶金技术》
CAS
CSCD
北大核心
2021年第2期117-121,共5页
Powder Metallurgy Technology
关键词
硬质合金
梯度结构
微观组织
晶粒尺寸
cemented carbides
gradient structure
microstructure
grain size
