淀粉模板法制备Ag-SnO2 电接触材料.

Ag-SnO2 composite powder was prepared by sol-gel method using Sn powder and AgNO3 as raw materials, citric acid as reductant and complexing agent and soluble starch aqueous solution as template. Subsequently, Ag-SnO2 electrical contact alloys were prepared using Ag-SnO2 composite powder as material by powder metallurgy. The obtained Ag-SnO2 composite powder and alloys were characterized through XRD and SEM. The decomposition process of starch paper precursor was analyzed via TG-DSC. Meanwhile, the microstructure and properties of Ag-SnO2 electrical contact alloys with different citric acid contents were also investigated. The results show that Ag-SnO2 electrical contact alloy is in good agreement with the tetragonal rutile SnO2 and face-centered cubic Ag, and the template has been removed without any impurities. SnO2 powder was uniformly dispersed in Ag matrix with the help of starch template. With the increasing of citric acidcontents, the physical properties of Ag-SnO2 electric contact alloy increased at first and then decreased. And the physical properties of Ag-SnO2 electrical contact alloy are the best when the ratio of n(C6H8O7):n(Ag++Sn4+)is 3:1. [ABSTRACT FROM AUTHOR]