Three types of compounds, i.e. MF type fluorides (including LiF, NaF, KF), MF2 type fluorides (including MgF2, CaF2, BaF2) and KN type potassium (including KF, KCl, KBr), were chosen as activated fluxes to evaluate the effect of weld shape, penetration and microstructure on the A-TIG Ti6Al4V alloy weld. The results show that good appearance and defect-free welded joints could be obtained with fluoride fluxes, except MgF2. Fluorides might act as antioxidants, which could keep weld bead from oxidation. In addition, bead width was significantly decreased in A-TIG with KF flux and MF2 type fluxes. Fluoride could effectively increase weld penetration than other halides (chloride and bromide) under the condition of same cationic. The KF fluoride in MF type had the greatest impact in increasing penetration, while MgF2 fluoride in MF2 type had the highest impact with larger penetration than that with KF fluoride. Furthermore, the solidification microstructure consisted of coarse and columnar grains throughout the complete fusion zone in both TIG and A-TIG welds. And the grains exhibited obvious refining effect in A-TIG weld, but it did not change the phase structure of weld bead.
高福样，廖志谦，熊进辉，等.船用钛合金焊接接头精细组织表征[J].焊接学报，2016，37(4)：124-128.Gao fuyang，Liao Zhiqian，Xiong Jinhui，etal.Microstructure of TIG welded Joint of marine titanium alloy[J].Transactions of the China Welding Institution，2016，37(4)：124-128.[2] Niagaj J.The use of activating fluxes for the welding of high-alloy steels by A-TIG method[J].Welding International，2003，17：257-261.[3] Nayee S G，Badheka V J.Effect of oxide-based fluxes on mechanical and metallurgical properties of dissimilar activating flux assisted-tungsten inert gas welds[J].Journal of Manufacturing Processes，2014，16：137-143.[4] Li D，Lu S，Li D，etal.Principles giving high penetration under the double shielded TIG process[J].Journal of Materials Science & Technology，2014，30(2)：172-178.[5] Tanaka M，Shimizu T，Terasaki T，etal.Effects of activating flux on arc phenomena in gas tungsten arc welding[J].Science and Technology of Welding and Joining，2000，5(6)：397-402.[6] 黄 勇，樊 丁，张 涵.表面活性剂对钛合金A-TIG焊熔深的影响[J].稀有金属材料与工程，2006，35(10)：1586-1588.Huang Yong，Fan Ding，Zhang Han.Effect of surface activating flux on weld penetration of A-TIG welding for titanium alloy[J].Rare Metal Materials and Engineering，2006，35(10)：1586-1588.[7] 刘凤尧，林三宝，杨春利，等.TIG焊活性剂对焊缝成形的影响[J].焊接学报，2002，23(1)：1-4.Liu Fengyao，Lin Sanbao，Yang Chunli，etal.Effect of activating fluxes on weld form in TIG welding of Stainless Steel an titanium alloy[J].Transactions of the China Welding Institution，2002，23(1)：1-4.[8] 黄 勇，樊 丁，樊清华，等.表面活性剂对铝合金直流正接A-TIG焊熔深的影响[J].焊接学报，2004，25(5)：60-66.Huang Yong，Fan Ding，Fan Qinghua.Effect of surface activating flux on welding penetration of A-TIG welding with DCSP mode of aluminum alloy[J].Transactions of the China Welding Institution，2004，25(5)：60-66.[9] Bang K S，Chirieleison G，Liu S.GTAW of titanium flux-cored wire with magnesium fluoride[J].Science and Technology of Welding & Joining，2005，10(5)：617-623.[10] 张兆栋，刘黎明，沈 勇，等.镁合金的活性电弧焊接[J].中国有色金属学报，2005，15(6)：912-916.Zhang Zhaodong，Liu Liming，Shen Yong，etal.Activating flux for arc welding of magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2005，15(6)：912-916.
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