液相还原法制备纳米晶Ag-50Ni合金的研究  

Study on Nanocrystalline Bulk Ag-50Ni Alloy Prepared by Aqueous Reducing Method

作　　者：曹中秋[1] 祝溪明[1] 李凤春[1] 

机构地区：[1]沈阳师范大学,辽宁沈阳110034

出　　处：《稀有金属材料与工程》2008年第7期1221-1224,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50771068);辽宁省自然科学基金(20062049)资助项目

摘　　要：采用液相还原法,随后在620℃、58MPa下经真空热压,制备了纳米晶Ag-50Ni块体合金,并通过X射线衍射(XRD)仪、扫描电镜(SEM/EDX)和透射电镜(TEM)研究了其显微组织结构。结果表明,Ag-Ni粉末的最佳合成工艺条件为:反应体系温度为70℃;还原剂水合肼(N2H4·H2O)浓度为2.5mol.L-1;反应物AgNO3浓度为1.5mol.L-1;反应物NiSO4的浓度为1.5mol.L-1;反应体系pH值为8。Ag-Ni粉末平均粒度约为45nm,黑色无定形形状。Ag-Ni粉末经真空热压后,晶粒尺寸有所长大,但仍保持纳米级尺度。合金致密度很高,由双相组成,显微组织均匀且无Ag网出现。A nanocrystalline Ag-50Ni bulk alloy has been prepared by hot pressing powders obtained by aqueous reducing method at 620℃ under a normal ＇pressure of 58 MPa. The microstructural characteristics of the sample were studied by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results show that the optimal processing parameters are as follows： the temperature of reaction system 70℃, the concentration of reactant AgNO3 1.5 mol·L^-1, the concentration of reactant NiSO4 1.5 mol·L^-1, the concentration ofreductant hydrazine hydrate 2.5 mol·L^-1, pH value of reaction system 8. Ag-Ni powder is black and amorphous solid. Its average particle size is about 45 nm. The sizes increase slightly but still remain in nano-size range after hot pressing. The alloy is composed of two-phases and has high density. Its microstructure is homogeneous and has no Ag net.

关 键 词：液相还原 Ag-50Ni合金 纳米晶 显微组织 

分 类 号：TB383.1[一般工业技术—材料科学与工程]