Stitch welding of Ti-6Al-4V titanium alloy by fiber laser

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• 作者：Cui LI^a ; Bin LI^b ; ^{licui0211@163.com} ; ^{lismile615@163.com} ; Ze-feng WU^a ; Xiao-yong QI^a ; Bing YE^a ; Ai-hua WANG^a ; ^b
• 关键词：Ti&ndash ; 6Al&ndash ; 4V titanium alloy ; fiber laser ; stitch welding ; welding parameter ; porosity
• 刊名：Transactions of Nonferrous Metals Society of China
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：27
• 期：1
• 页码：91-101
• 全文大小：5246 K
• 卷排序：27

文摘

Stitch welding of plate covered skeleton structure of Ti–6Al–4V titanium alloys has a variety of applications in aerospace vehicle manufacture. The laser stitch welding of Ti–6Al–4V titanium alloys was carried out by a 4 kW ROFIN fiber laser. Influences of laser welding parameters on the macroscopic geometry, porosity, microstructure and mechanical properties of the stitch welded seams were investigated by digital microscope, optical microscope, scanning electron microscope and universal tensile testing machine. The results showed that the three-pipe nozzle with gas flow rate larger than 5 L/min could avoid oxidization, presenting better shielding effect in comparison with the single-pipe nozzle. Porosity formation could be suppressed with the gap between plate and skeleton less than 0.1 mm, while the existing porosity can be reduced with remelting. The maximum shear strength of stitch welding joint with minimal porosity was obtained by employing laser power of 1700 W, welding speed of 1.5 m/min and defocusing distance of +8 mm.