摘要
以Ag板、Cu板和Ni板为原料,经合金冶炼工艺制得的AgCuNi合金采用内氧化法制备了AgCuONiO电接触复合材料。主要考察了氧分压、氧化温度等工艺参数对AgCuONiO材料的氧化率、硬度和电阻率的影响,并探究其微观机制。采用扫描电镜、维氏硬度计和电导率仪等对AgCuONiO材料的微观结构和物理性能进行了表征。结果表明:随着氧压从0.021 MPa增加至1.0 MPa,样品氧化层厚度及氧化率呈先上升至波峰而后下降并趋于平缓的变化趋势,而氧化层的电阻率性能变化规律呈近似“V”型分布态;氧化温度为600℃~800℃时,随着氧分压的增加,氧化层硬度呈平缓上升趋势。内氧化法制备AgCuONiO电接触复合材料的最优工艺参数:氧化温度区间为750℃~800℃、氧分压0.5 MPa。微观组织分析结果表明,随着氧化温度的升高,氧化层出现由氧化物颗粒偏析构成的大量晶界网络,形成晶界偏析效应。当氧化温度升至800℃或850℃时,氧化层微观组织中小晶界合并消亡并长大形成大晶界组织;当氧化温度850℃时,大晶界组织内部存在较多呈弥散分布的氧化物析出颗粒,同时在界面处出现了Ag成分富集区,导致整个氧化层的硬度分布不均匀。AgCuONiO材料的内氧化机制是由内氧化前端氧化物形核与沉淀颗粒长大之间相互竞争的结果,沉淀析出相在浓度梯度等扩散因素驱动下发生颗粒粗化。
By using Ag plate,Cu plate and Ni plate as raw materials,AgCuNi alloys were prepared by melting process and then AgCuONiO electrical contacts were prepared by internal oxidation process.Effect of oxidation parameters on oxidation rate,hardness,resistivity and its microstructure of AgCuONiO contacts were investigated by Scanning Electron Microscopy,Metallographic Microscope,Vickers Hardness tester and Conductivity Meter.The results showed that with the oxygen pressure increased from 0.021 MPa to 1.0 MPa,the thickness and oxidation rate of the oxide layer of AgCuONiO contact firstly increased up to the peak,then decrease and tend to be smooth,while its resistivity appeared to be Approximately"V"-type distribution.With the increase of the oxygen partial pressure,the hardness of oxide layer gradually increased at 600℃~800℃.The optimal process parameters for preparing AgCuONiO electrical contacts were as followed:the oxidation temperature zone ranged from 750℃to 800℃,and the oxygen partial pressure at 0.5 MPa.It can be observed that with the increase of the oxidation temperature,a large amount of grain boundary network composed of oxide particle segregation appeared in the oxide layer,which led to grain boundary segregation effect.With the oxidation temperature increased up to 800℃or 850℃,small grain boundaries in the oxide layer merged and finally form large grain boundary.When the oxidation temperature at 850℃,more precipitated oxidized particles distributed inside the large grain boundary were observed.Meanwhile,the enrichment of Ag existed on the grain boundary and then resulted in inhomogeneous hardness distribution of the whole oxide layer.The microstructure of internal oxidation mechanism of AgCuONiO material is determined by the result of competition between the growth of the precipitated particles and the nucleation of new oxides at the internal oxidation front.Under the internal oxidation controlled by thermodynamic and kinetic factors such as concentration gradient,particle coarsening phenomen
作者
吴新合
祁更新
陈晓
张继
沈涛
穆成法
吴艳芳
张宇星
王开旭
吕鹏举
张林
WU Xinhe;QI Gengxin;ZHANG Ji;CHEN Xiao;SHEN Tao;MU Chengfa;WU Yanfang;ZHANG Yuxing;WANG Kaixu;LV Pengju;ZHANG Lin(Wenzhou Hongfeng electrical alloy Co.,ltd,Zhejiang Wenzhou 325603,China;Zhejiang-California International NanoSystems Institute,Zhejiang Hangzhou 310058,China;School of Materials Science and Engineering,Zhejiang University,Zhejiang Hangzhou 310027,China)
出处
《电工材料》
CAS
2021年第3期3-8,23,共7页
Electrical Engineering Materials
基金
浙江省科技计划项目(2018C01127)
关键词
电接触材料
AgCuONiO
内氧化法
氧化温度
电学性能
硬度
颗粒粗化
electrical contact material
AgCuONiO
Internal oxidation method
oxidation parameter
electrical properties
hardness
particle coarsening
