Preparation and properties of Ni-coated WC powder and highly impact resistant and corrosion resistant WC-Ni cemented carbides  

Ni包覆WC粉体及高抗冲击耐腐蚀WC-Ni硬质合金的制备和性能

作　　者：Fan-lu MIN Song-bai YU Sheng WANG Zhan-hu YAO Jacques Guillaume NOUDEM Si-jin LIU Jian-feng ZHANG 闵凡路;于淞百;汪升;姚占虎;Jacques Guillaume NOUDEM;刘四进;张建峰(河海大学岩土力学与堤坝工程教育部重点实验室,南京210098;河海大学土木与交通学院,南京210098;河海大学力学与材料学院,南京210098;中交隧道工程局有限公司,北京100102;CRISMAT-ENSICAEN(UMR-CNRS 6508),Universitéde Caen-Basse-Normandie,Caen,F-14050,France;中铁十四局集团有限公司,济南250101)

机构地区：[1]Key Laboratory of Geomechanics and Embankment Engineering,Ministry of Education,Hohai University,Nanjing 210098,China [2]College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China [3]College of Mechanics and Materials,Hohai University,Nanjing 210098,China [4]CCCC Tunnel Engineering Company Limited,Beijing 100102,China [5]CRISMAT-ENSICAEN(UMR-CNRS 6508),Universitéde Caen-Basse-Normandie,Caen,F-14050,France [6]China Railway 14th Bureau Group Co.,Ltd.,Jinan 250101,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第6期1935-1947,共13页中国有色金属学报（英文版）

基　　金：the financial supports from the National Natural Science Foundation of China (Nos. 51778213, 52078189);the Fundamental Research Funds for the Central Universities, China (No. B200202073)。

摘　　要：WC powders were uniformly coated by Ni nanoparticles through a combined chemical co-precipitation and subsequent high temperature hydrogen reduction strategy(abbreviated as CM-WCN),and then were consolidated by vacuum sintering at 1450°C for 1 h to obtain WC−Ni cemented carbides.The microstructure and properties of the as-consolidated CM-WCN were investigated.The average grain size of WC in the consolidated CM-WCN was calculated to be in the range of 3.0−3.8μm and only few pores were observed.A relative density of 99.6%,hardness of HRA 86.5 and bending strength of 1860 MPa were obtained for the CM-WCN−10wt.%Ni,and the highest impact toughness of 6.17 J/cm^(2 )was obtained for the CM-WCN−12wt.%Ni,surpassing those of the hand mixed WC−Ni(HM-WCN)cemented carbides examined in this study and the other similar materials in the literature.CM-WCN cemented carbides possess excellent mechanical properties,due to their highly uniform structure and low porosity that could be ascribed to the intergranular-dominated fracture mode accompanied by a large number of plastic deformation tears of the bonding phase.In addition,the corrosion resistance of CM-WCN was superior to that of HM-WCN at the Ni content of 6−12 wt.%.采用化学共沉淀−高温氢还原工艺制备纳米Ni均匀包覆的WC复合粉体(简称CM-WCN),在1450℃下真空烧结1 h,获得WC−Ni硬质合金,并对其组织及性能进行研究。结果表明,CM-WCN硬质合金中WC的平均晶粒度为3.0~3.8μm,仅观察到少量孔隙。CM-WCN−10%Ni(质量分数)的相对密度、硬度及抗弯强度分别为99.63%、HRA 86.5及1860 MPa,CM-WCN−12%Ni(质量分数)的最高冲击韧性为6.17 J/cm^(2),优于本文中手混法制备的WC−Ni(HM-WCN)硬质合金及文献报道同类合金的性能。由于结构均匀性及低孔隙率,CM-WCN硬质合金具有优异的力学性能,其主要断裂模式为穿晶断裂,并伴随黏结相塑性形变。此外,当Ni含量为6%~12%(质量分数)时,CM-WCN比HM-WCN硬质合金的耐腐蚀性能更好。

关 键 词：WC−Ni cemented carbides chemical co-precipitation method high temperature hydrogen reduction strategy Ni content microstructure impact toughness corrosion resistance 

分 类 号：TG135.5[一般工业技术—材料科学与工程]