Properties Of Sn-9Zn Solder Alloy With Mixed Rare Earth Carbonate

As the melting point of Sn-Zn solder was the closest to the traditional Sn-Pb solder,it become the best matching choice of alternative brazing filler metal one.However,there were some shortcomings in the oxidation resistance and the wettability of the Sn-Zn solder,which limit its development in brazing.Seeking cost-effective methods to improve the performance of Sn-Zn solder was an urgent need for the development of Sn-Pb solder.Based on the characteristics of rare earth elements,rare earth carbonate was chose to add into the solder this paper.Mixed rare earth carbonate was added into solder directly,which not only reducing the cost but also improving the properties of Sn-Zn Sn-Zn solder.First,using the existing mature technology to ammonium bicarbonate leach rare earth ore and rare earth production waste mud,and got mixed rare earth carbonate by simplest production process.Then,different origins self-made mixed carbonate rare earths were added into Sn-Zn solder,the oxidation resistance,welding reliability,mechanical properties and melting point,wetting spread and other performances of the Sn-Zn solder which added mixed rare-earth carbonate and rare earth mixed with lanthanum-cerium were compared.The results showed that the effect of rare earth carbonate on the oxidation resistance of brazing filler metal was more obvious than that of mixed rare earth lanthanum cerium.When the amount of added rare earth carbonate was 0.09%,the intermetallic compound layer of brazing filler metal was the thinnest,the welding reliability was the best,and the improvement of the hardness of the brazing filler metal was more effective.When the amount of added rare earth carbonate was 0.09%,the spread and spread ratio of brazing filler metal were reaching to the maximum value,the melting range of brazing filler metal was shortest,the flowability was best,the melting heat(peak area of heat absorption)was good,and the antioxidant was best.Last,comparing the performance indicators from two kinds of optimum adding amount of samples,the results showed that when the total amount of rare earth ions in the two kinds of rare earth elements were 0.09%,Compared to the original one,the wetting and spreading area of the waste mud samples was 6.87% higher than that of,the melting point increased 2.1?,the melting temperature range decreased 0.3?,the latent heat of fusion increased 0.85 J / g,the IMC layer thickness decreased 1.9 ?m,the micro-Vickers hardness increased 0.8,the shape of the mark was more regular which more closer to the square,and the oxidation resistance and slag rate were had little difference.Therefore,all kinds of properties of the solder samples which rare earth carbonate come from rare earth production waste mud were more excellent than those rare earth carbonate come from rare earth ore when the total amount of rare earth ions in the mixed rare earth carbonate was 0.09%.