摘要
以水热法合成的Co_(3)O_(4)空心球粉体和化学银粉为原料,运用粉末冶金技术调控不同成型压力、烧结制度等工艺参数制备Ag/Co_(3)O_(4)电接触材料;采用扫描电镜(SEM)、X射线衍射(XRD)、金相显微镜等对其形貌、物相及金相组织进行了表征;对比分析压制烧结条件对电阻率、硬度和密度(致密度)等物理性能的影响。结果表明,100℃水热反应13 h合成的Co_(3)O_(4)为粒径2.2μm的空心微球粉体。1000 MPa、850℃保温6 h初压初烧后,进一步经复压复烧(1000 MPa、800℃保温6 h)处理,得到的Ag/Co_(3)O_(4)材料物理性能得到提高,其电阻率低至2.78μΩ·cm,硬度(HV0.5)高至71.7,密度为9.22 g/cm^(3)(致密度95.6%),表明复压复烧工艺有助于实现Co_(3)O_(4)颗粒增强相在银基体上的均匀弥散分布,降低Ag/Co_(3)O_(4)材料的孔隙率,提高其致密度,改善其综合物理性能。
With Co_(3)O_(4) hollow sphere powder prepared by a hydrothermal method and silver powder synthesized by a chemical method as the raw materials,Ag/Co_(3)O_(4) electrical contact materials were prepared by powder metallurgy technology through controlling various molding pressures and sintering processes.Their morphology,phase structure and metallographic microstructure of Co_(3)O_(4) powders and Ag/Co_(3)O_(4) electrical contact materials were characterized by SEM,XRD and metallographic microscopy.Effects of pressing and sintering conditions on physical properties such as resistivity,hardness and density(densification)were compared and analyzed.The results showed that hollow micro spherical Co_(3)O_(4) powder synthesized by hydrothermal reaction at 100℃for 13 h had 2.2μm of particle size.The physical properties of Ag/Co_(3)O_(4) electrical contact materials were improved,with the lowest resistivity of 2.78μΩ·cm,the highest hardness(HV0.5)of 71.7,and density of 9.22 g/cm3(relative density 95.6%),after the initial pressing-sintering process(1000 MPa and 850℃for 6 h)and following repressing-resintering process(1000 MPa and 800℃for 6 h).The results showed that the repressing-resintering process was helpful to make Co_(3)O_(4) phase homogeneously dispersed in the silver matrix,thereby reducing the porosity of the Ag/Co_(3)O_(4) contact materials,increasing its density,and then improving its comprehensive physical properties.
作者
杨芳儿
秦海波
张继
穆成法
沈涛
郑晓华
YANG Fang-er;QIN Hai-bo;ZHANG Ji;MU Cheng-fa;SHEN Tao;ZHENG Xiao-hua(College of Materials Science and Engineering,Zhejiang University of Technology,Hangzhou 310014,China;School of Materials Science and Engineering,Zhejiang University,Hangzhou 310058,China;Wenzhou Hongfeng Electrical Alloy Co.Ltd.,Wenzhou 325603,Zhejiang,China)
出处
《贵金属》
CAS
北大核心
2022年第1期27-33,共7页
Precious Metals
基金
浙江省重点研发计划(No.2017C01051)。
关键词
Ag/Co_(3)O_(4)
电接触材料
复压复烧
物理性能
显微组织
Ag/Co_(3)O_(4)
electrical contact materials
re-pressing and re-sintering
physical properties
metallographic microstructure
