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Titanium plate laser -TIG Arc Hybrid Welding Research

Author: CaoYunMing
Tutor: LiuLiMing
School: Dalian University of Technology
Course: Materials joining technology
Keywords: Titanium TIG Defect Hybrid welding Mechanical behavior
CLC: TG457.1
Type: Master's thesis
Year: 2011
Downloads: 191
Quote: 1
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Abstract


Titanium and titanium alloys have high specific strength, light weight, high temperature resistance, corrosion resistance, good processing properties, etc., in the aerospace, chemical, medicine and other fields has been widely used. In actual welding titanium plate, due to low equipment cost, less energy consumption and other advantages, TIG welding become a common welding process. It also has a low melting efficiency, melting depth and other shortcomings, taking into account the physical characteristics of titanium itself and a strong high-temperature activity, resulting in poor stability TIG weld, welding productivity is low, these factors restrict the TIG welding process in titanium Plate welding application and development. Therefore, an urgent need to develop a low-power, low-cost and efficient welding titanium plate new technology. This paper carried out a low-power laser-TIG arc hybrid welding technology research, comparative analysis of process parameters on weld explore the effect of low-power laser to improve the mechanism for backing weld forming and welding processes used in the composite plate welding of titanium. The results show that: 1. Use of low-power laser-TIG arc hybrid welding process, be able to weaken or eliminate defects in welded joints on the back. Compared to the TIG welding, significantly improve the penetration ability of the welding arc. By comparing the different process parameters on weld shape, and found that under the experimental conditions TIG welding process is difficult to get a good shape welded joints. As the welding heat input increases and bevel angle increases, forming the back seam improved. Under the same arc current, the laser-TIG arc hybrid welding process to obtain a good shape of the welded joint. By morphology of the two welded joints comparative study found that, compared to TIG welding, laser-TIG arc hybrid welding joints melt zone acicular α phase gradually increased, and the phase within the grains were rules basket like distribution. Composite weld heat affected zone width slightly larger than the TIG welds. (2) the arc welding process by morphology observed that the duration of the laser pulse, the circular arc into a conical shape, the arc portion of the groove down to the bottom, this phenomenon shows that the arc energy dispersed in a groove on both sides by a concentrated in the center of the weld, the TIG welding of the laser energy applied is more concentrated arc melting is to enhance the ability of the important reasons; laser - arc weld molten zone composite connectors change in direction of the grain growth, which is a low power laser action mainly under the influence of the individual energy input and TIG arc conduction, thereby changing the weld puddle temperature gradient, leading to a change in direction of grain growth. 3 using the optimized process parameters to achieve the three thicknesses 12,15,18 mm titanium plate butt welding. Mechanical properties showed that under the experimental conditions three different thicknesses of base metal connectors tensile strength can reach more than 95%; weld toughness average reached more than 85% of base metal; high cycle fatigue test cycle weld 500Mpa stress level in the number of cycles of 3-10 million times.

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CLC: > Industrial Technology > Metallurgy and Metal Craft > Welding, metal cutting and metal bonding > Welding process > Welding of a variety of metal materials and components > Welding of metallic materials
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