银镁镍合金的微观组织及物相构成  

Microstructure and Phase Analysis of Ag-Mg-Ni Alloy

作　　者：杨唯一[1] 谢明[1] 陈永泰[1] 王剑华[2] 张吉明[1] 王松[1] 

机构地区：[1]昆明贵金属研究所稀有金属综合利用新技术国家重点实验室,云南昆明650106 [2]昆明理工大学分析测试中心,云南昆明650093

出　　处：《稀有金属》2016年第10期969-975,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51267007);国家自然科学基金-云南联合基金项目(U1302272);云南省院所技术开发专项项目(2013DC016);云南省创新团队项目(2012HC027)资助

摘　　要：采用真空熔炼和双辊轧制技术制备了Ag-0.24Mg-0.29Ni(%,原子分数)合金片材,通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和高分辨透射电镜(HRTEM)对Ag-0.24Mg-0.29Ni合金片材的微观组织及物相构成、第二相的存在形式及形貌分布进行了观察表征和形貌分析。结果表明:微量Mg固溶在Ag基体中形成Ag-Mg代位固溶体;晶内的螺位错处易于富集Mg,Mg与Ag基体形成第二相Mg54Ag17并析出,第二相Mg54Ag17与Ag基体呈现共格或者半共格关系,富集在缺陷处的Mg影响了面心立方结构Ag(100)的消光,使(100)面出现反射。微量Ni以颗粒状弥散分布在银镁固溶体中,在晶界上析出的第二相MgNi_2化合物,都对银基体起到晶粒细化和弥散强化的作用;在镍偏聚的缺陷区域,易聚集形成富镍含氧的氧化物,使合金的组织不均匀,可能对合金以后的内氧化进程及性能产生不利的影响。The phases and microstructures of Ag-0.24Mg-0.29Ni（ % , atom fraction） alloys and the existing form, morphology, distribution of the second phases which were produced by vacuum smelting and rolling were characterized by X-ray diffraction （ XRD）, scanning electron microscopy （SEM）, transmission electron microscope （TEM） and high resolution transmission electron microscopy （ HRTEM ） respectively. The results showed that Mg was solid dissolved in the Ag-Mg solid solution and concentrated in the screw dislocation; Mg and Ag formed second phase Mg54Ag17, Mg affected the extinction of face-centered cubic structure Ag （100） and made the （110） crystal surface reflect. The second phase Mg54Ag17 had coherent or semi-coherent relation with the matrix. Nickel particles which existed as simple substance were distributed homogeneously in Ag-Mg solid solution; MgNi： which existed as second phase was precipitated on the grain boundary. They all had the effect of dispersion strengthening and grain refinement on the matrix. Ni easily formed nickel-oxide in the defect areas. It might have uneven microstructure and cause unfavorable influence on performance and the later process of internal oxidation.

关 键 词：Ag-0.24Mg-0.29Ni合金 第二相 物相 微观组织 

分 类 号：TG13[一般工业技术—材料科学与工程]