| The activating flux TIG?A-TIG?welding is of great importance for its improved welding productivity and weld quality,and has been widely studied.However,former studies on A-TIG welding mainly concentrate on the stainless steel and titanium alloys.The study for aluminum alloys has been few reported.In this study,the effects of activating fluxes on LY12 aluminum alloy were studied.Firstly,five different activating fluxes including Ca Cl2,Ca F2,Na Cl,Al F3 and Na F were investigated.The arc shapes and weld formations of A-TIG were compared to TIG under the same welding parameters.The results show that the arc shapes are different for traditional TIG and A-TIG.Additionally,the effects of different activating fluxes are different.The stability of arc is affected by the types of activating fluxs.The arc is stable with Ca F2?Na Cl or Na F,while the arc is unstable with Ca Cl2 and Al F3.Because of the large particle size,Na Cl is difficult to deposit on the surface of the test plate.Thus,the arc cannot steadily act on the surface during welding.The weld formations also change with the activating fluxes,which are better than those without flux.The weld formations are good with flux Al F3 and Na F,while the weld formation is poor with Ca F2.Compared with traditional TIG welding,the weld penetration depth of A-TIG welding also has been changed.The effects of activating fluxes on penetration depth are different.With the addition of flux Na Cl,the penetration depth increases.However,when Na F is applied,the weld penetration depth reduces.Finally,the result shows that the depth-to-width ratio and formation of weld are both improved by using an activating flux which is mixed with Na Cl,Na F and Ca F2 by 1:1:2.Using this activating flux,the A-TIG welding can significantly reduce the heat input and improve the welding speed,without affecting the strength of the weld joint.As a result,this A-TIG welding for LY12 can further improve industrial efficiency. |
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