直流电弧等离子体法制备超细银钯合金粉  

Study on the Preparation of Ultrafine Silver-Palladium Alloy Powders by DC Arc Plasma Evaporation

作　　者：张振忠[1] 江成军[1] 赵芳霞[1] 段志伟[1] 曹娟[1] 

机构地区：[1]南京工业大学,江苏南京210009

出　　处：《稀有金属材料与工程》2008年第11期1987-1991,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(10502025);省高校自然基金(05KJB1300421)资助

摘　　要：以感应熔炼法制得的银钯合金块为原料,采用自行研制的高真空双枪直流电弧金属纳米粉连续制备设备,结合对合金制粉蒸发机制的探讨,成功制得了超细银钯合金粉体。利用XRF、XRD、TEM、SAED和DSC等测试手段对样品的成分、相组成、形貌、晶体结构、平均粒径和粒径分布进行了分析。结果表明,在低温、低蒸发率条件下,即使是采用均匀单相合金块体也不能直接按照原始材料成分直接蒸发冷凝制得银钯合金粉体,而存在元素竞争蒸发现象;通过提高母合金中Pd元素含量和升高熔体温度的方法,成功制备出了成分为Ag84.38Pd14.85的超细Ag-Pd合金粉体;实验制备出的超细粉体成链球状,平均粒径为62.15nm,DSC分析显示粉体的熔点有明显的降低。Based on the study on the mechanism of alloy evaporation, Ag-Pd alloy ultrafines have been prepared successfully by the high-vacuum, two-electrode DC Arc Plasma apparatus which is designed and fabricated by our self, using Ag-Pd alloy made by induction smelting as raw material. The chemical composition, phase component, morphology, crystal microstructure and mean particle size of powder were characterized by X-ray fluorescence （XRF）, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and the corresponding selected area electron diffraction （SAED）, differential scanning calorimeter （DSC）. The results showed that it is impossible to obtain Ag-Pd alloy powders by evaporation-condensation process at low temperature and evaporation rate even using homogeneous, single-phase bulk alloy as raw material because of Ag and Pd evaporation. By increasing amount of Pd in the Ag-Pd master alloy and elevating the temperature of the melting body, Ags4.38Pd14.85 alloy ultrafines have been prepared successfully, which present chain-spherical with 62.15 nm in particle size. The DSC result shows that the powders＇ melting point has markedly be dropped.

关 键 词：感应熔炼 直流电弧蒸发 超细银钯粉 制备 

分 类 号：TB383.3[一般工业技术—材料科学与工程]