The Study Of Soldering Flux For Aluminum

Aluminum and it alloy had been used in many fields for their good properties. But there is a layer of oxide film on their surface that leads to solder difficult, which holds back its application gravely. The most important point is preparing an effective flux to solve this problem. Now some better fluxes have been prepared overseas, but those are expensive. Domestic studies are most in the stage of laboratory, so preparing soldering flux for aluminum and its alloy is significant in both research and economy.The aim of our study is to prepare a soldering flux applying to fill flux cored wire. The content include finding appropriate components, studying appropriate proportion and optimization flow, and preparing better performance and economical soldering flux.The method of finding appropriate components is filtration. Firstly, potentially appropriate substances were selected. Second, solder ability was tested. Finally, the substances which have better solder ability and lower price were selected.The results show: hydroxyl polyamine's wet ability is better than hydroxylamine carboxyl ate and other organic amine. Adding 50%HF in hydroxyl polyamine can improve wet ability and solder ability highly, enhance the rate of removing film by more than 10% at the same time; Corrosion-inhibiting rate of SC-201 rose to 80% and without change with time went on, also, it has good solder ability. Although BTA is better than SC-201 in corrosion-inhibiting rate and wet ability for copper under the condition of room temperature, it can not been used in higher temperature and no corrosion-inhibit ability for aluminum, so it did not be chosen; Fluorocarbon surfactant has higher coking temperature. It can improve wet ability heavily if added in solder flux, so it had been selected; Heavy metal-Ag,Zn,Sn,Si can improve creep resistance and fatigue strength, so they were added as auxiliary agents; Hydro rosin ester has good expending rate, fluidity and viscosity, it is the most appropriate carrier.The rate of removing film, expending, corrosion-inhibit ability and tensile strength were tested according to state standard, the effect of proportion, pH, time of concentration on solder ability have been studied. The optimization mechanics condition had been...