摘要
利用Thermo-Calc热力学软件与同步热分析仪(DSC)、X射线衍射仪(XRD)、透射电镜(TEM)等设备实际检测相结合的方法,研究了超低温处理对WC-12Co超细晶硬质合金微观组织结构的影响及其深冷强化机制,同时也探究了硬质合金中Co相的转变特点。研究结果表明:深冷处理可促进合金中γ-Co(fcc晶体结构)转变为α-Co(hcp晶体结构);在SEM下观察,未发现深冷处理前后合金的组织形貌有明显变化,但是在TEM下观察,可发现γ-Co(fcc晶体结构)转变为α-Co后原γ-Co中的晶体缺陷被大量消除;深冷处理后合金的强化主要是由于γ-Co转为α-Co后原γ-Co中的晶体缺陷被大量消除和类似于相变诱发塑性(TRIP)、第二相强化的综合作用所致;合金中γ-Co不能完全转变为α-Co是由于WC晶界的钉扎作用所致。
The effect of deep cryogenic treatment (DCT)on microstructure of WC-12Co ultrafine grained cemented carbide and its DCT strengthening mechanism were studied using thermodynamic software Thermo-Calc,thermal analyzer,X-ray diffractometric (XRD),transmission electron microscopes (TEM)and other apparatuses.At the same time,the change characteristics of Co phase in cemented carbide were also investigated.The results showed that DCT could promote the γ-Co (FCC crystal structure)translate into α-Co (HCP structure)in alloy;there was no significant change in morphology after DCT when observed by scanning electron microscope (SEM),but when observed by TEM,it could be found that a large number of crystal defects in γ-Co could be diminated after T-Co translated into α-Co ;the strengthening of alloy after DCT were mainly due to that a large number of crystal defects in γ-Co could be eliminated after γ-Co translated into α-Co and the combined effects of similar to transformation induced plasticity effect and second phase strengthening;γ-Co in alloy could not completely turn into α-Co,which resulted from pinning of WC grain boundary.
作者
张贺佳
续永刚
马红英
李正团
王文广
Zhang Hejia;Xu Yonggang;Ma Hongying;Li Zhengtuan;Wang Wenguang(Department of Machine Engineering,Shifiazhuang Vocational Technology Institute,Shijiazhuang 050081,China;Chengde Chengsteel Cold Rolled Sheet Group Co.,Ltd.,Chengde 067002,China;School of Materials Science and Engineering,University of Science and Technology Beijing,Belting 100083;School of Mechanical Engineering,Liaoning Shihua University,Fushun 113001,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2018年第11期1149-1155,共7页
Chinese Journal of Rare Metals
基金
国家工信部科技重大专项课题项目(2012ZX04003061)资助
关键词
超细晶硬质合金
超低温处理
相变
晶体结构
ultrafine-grained cemented carbides
deep cryogenic treatment
phase transition
crystal structure
