Experimental Study On The Effect Of Trace Elements On The Oxidation Resistance Of Tin

Because of tin’s features of low melting point, non-toxic, corrosion resistance, well ductility, good shape and it can be formed into alloy with many metals, tin is applied to electronic industry widely and the use of tin solder is increased. The use of lead will pollute the environment, damage human health, which requires the new lead-free solder takes place of the traditional Sn-Pb solder. However if the existing lead-free solder is used at high temperatures, it would extremely easy to be oxidized, and produce large amounts of oxidizing slag, affect the use of the hot tin, solder, etc.. It also affects the welding process and the quality of the products. In order to achieve suitable for lead-free solder antioxidant formula of the tin alloy, the author of this article improves the oxidation resistance of tin by adding trace element method, regarding development and optimization in order to achieve suitable for lead-free solder antioxidant formula of the tin alloy.This article through to the tin melt adding trace amounts of P, Ni, Al, Y element to study the oxidation resistance and wettability, and based on this research the Sn-P-Y and Sn-P-Ni ternary oxidation resistance and wettability of lead-free solder alloy, by scanning electron microscopy (SEM) and energy spectrum analysis of the solder alloy surface oxidation, thus discusses the lead-free solder alloy trace elements to improve the mechanism of oxidation resistance.Test results of this paper show that trace elements, Al, P, Y to add tin can improve the melt oxidation resistance and wettability, and trace amounts of Ni element but will improve weakly its oxidation resistance and wettability. Under320℃, in terms of relatively pure tin, Sn-0.02%P alloy oxidation resistance are improved. When the Al content of0.02%, Al, Sn-0.02%of alloy oxidation resistance and wettability have improved.When Y to add content is0.01%and Sn-0.01%Y alloy oxidation resistance and wettability have significantly improved.Energy spectrum analysis, enrichment of P and Al element in solder alloy surface, form a barrier layer, to prevent further oxidation.Trace amounts of P, Ni, Al, Y element were added into the tin melt to study the oxidation resistance, on the basis of research, and also to Sn-P-Y ternary alloy was studied, and experimental results show that the oxidation resistance performance has improved significantly, than binary alloy and tin is excellent, but the overall wettability and pure tin ratio has fallen. The Sn-0.02%P-0.02%Y oxidation resistance of alloys and wettability are superior. Colorimetric analysis Sn-0.02%P-0.02%Y alloy under the high temperature320℃, tests showed that the oxidation of5hours still can keep bright and showed good antioxidant properties. Scanning electron microscopy analysis showed that P element in the enrichment of the surface height of the solder alloy, forming a layer of protective film, to achieve the effect of antioxidant.In the Sn-P-Ni alloy, experimental results show that the oxidation resistance performance has improved significantly, than binary alloy and tin is excellent, but the overall wettability and pure tin ratio has fallen. The Sn-0.02%P-0.01%Ni oxidation resistance of solder alloys and wettability are superior. Colorimetric analysis Sn-0.02%P-0.01%Ni alloy under the high temperature320℃, tests showed that the oxidation of5hours still can keep bright and showed good antioxidant properties. Scanning electron microscopy analysis showed that P element in the enrichment of the surface height of the solder alloy, forming a layer of protective film, protect the solder alloy was further oxidation.