Comparison of microstructure, mechanical properties, and residual stresses in tungsten inert gas, laser, and electron beam welding of Ti–5Al–2.5Sn titanium alloy

2017 ◽  
Vol 233 (7) ◽  
pp. 1336-1351
Author(s):  
Massab Junaid ◽  
Khalid Rahman ◽  
Fahd Nawaz Khan ◽  
Nabi Bakhsh ◽  
Mirza Nadeem Baig
Keyword(s):  
Electron Beam ◽  
Residual Stresses ◽  
Power Density ◽  
Fusion Zone ◽  
High Power ◽  
Electron Beam Welding ◽  
Inert Gas ◽  
High Power Density ◽  
Cooling Rates ◽  
Zone Width

Electron beam welding (EBW), pulsed Nd:YAG laser beam welding (P-LBW), and pulsed tungsten inert gas (P-TIG) welding of Ti–5Al–2.5Sn alloy were performed in order to prepare full penetration weldments. Owing to relatively high power density of EBW and LBW, the fusion zone width of EBW weldment was approximately equal to P-LBW weldment. The absence of shielding gas due to vacuum environment in EBW was beneficial to the joint quality (low oxide contents). However, less cooling rates were achieved compared to P-LBW as an increase in heat-affected zone width and partial α′ martensitic transformation in fusion zone were observed in EBW weldments. The microstructure in fusion zone in both the EBW and P-TIG weldments comprised of both acicular α and α′ martensite within the prior β grains. Hardness of the fusion zone in EBW was higher than the fusion zone of P-TIG but less than the fusion zone of P-LBW weldments due to the observed microstructural differences. Notch tensile specimen of P-LBW showed higher load capacity, ductility and absorbed energy as compared to P-TIG and EBW specimens due to the presence of high strength α′ martensite phase. Maximum sheet distortions and tensile residual stresses were observed in P-TIG weldments due to high overall heat input. The lowest residual stresses were found in P-LBW weldments, which were tensile in nature. This was owing to high power density and higher cooling rates in P-LBW operation. EBW weldment exhibited the highest compressive residual stresses due to which the service life of EBW weldment is expected to improve.

Features and Application of Electron Beam Welding Technology

2015 ◽  
Vol 1120-1121 ◽  
pp. 1308-1312
Author(s):  
Ming Feng Li ◽  
Zheng Hong Zhu
Keyword(s):  
Electron Beam ◽  
Power Density ◽  
High Power ◽  
Electron Beam Welding ◽  
High Ratio ◽  
High Power Density ◽  
High Quality ◽  
Welding Equipment ◽  
Welding Technology ◽  
Wide Range

Electron beam welding technology is a mature special welding technology. The advantage of electron beam welding like these: high power density, high ratio of depth-to-width, high-quality welds. Electron beam welding equipment has been independently developed by tracking and bringing in. Electron beam welding technology has a wide range of applications in the aerospace, automotive, medical and other branches of industry, the field of applications is also expanding with the improved welding equipment. According to the demand of research and market, Electron beam welding technology will move toward the direction of universal, integrated, information-oriented in the future.

Parametric Study of the Two-Dimensional Keyhole Model for High Power Density Welding Processes

1994 ◽  
Vol 116 (1) ◽  
pp. 209-214 ◽  
Author(s):  
Charn-Jung Kim ◽  
Sangken Kauh ◽  
Sung Tack Ro ◽  
Joon Sik Lee
Keyword(s):  
Power Density ◽  
High Power ◽  
Parametric Study ◽  
Arc Welding ◽  
Electron Beam Welding ◽  
High Power Density ◽  
Two Dimensional ◽  
Position Correction ◽  
Welding Processes ◽  
The Mathematical Model

This study presents a parametric study of the two-dimensional steady-state keyhole model for high power density welding processes. Keyhole formation is common to electron beam welding, laser welding, and plasma arc welding, all of which are important techniques for high-quality, high-precision welding. Computation was performed by adopting a recently developed concept of the position correction and modifying it suitably for the problem of interest. The dimensionless parameters pertaining to the model were identified and the influence of each parameter was investigated separately. Although the mathematical model employed here has been used in previous studies, a thorough investigation successfully revealed new features that have not been previously recognized in the literature.

Emittance of high-power-density electron beam

Vacuum ◽  
1999 ◽  
Vol 55 (3-4) ◽  
pp. 223-233 ◽  
Author(s):  
Jan Felba
Keyword(s):  
Electron Beam ◽  
Power Density ◽  
High Power ◽  
High Power Density

High‐power‐density electron‐beam‐sustained laser

1983 ◽  
Vol 54 (4) ◽  
pp. 458-462 ◽  
Author(s):  
M. Casey ◽  
P. W. Smith ◽  
M. H. R. Hutchinson
Keyword(s):  
Electron Beam ◽  
Power Density ◽  
High Power ◽  
High Power Density

Microstructure, mechanical properties and residual stress distribution in pulsed tungsten inert gas welding of Ti–5Al–2.5Sn alloy

2018 ◽  
Vol 233 (10) ◽  
pp. 2030-2044
Author(s):  
Massab Junaid ◽  
Fahd Nawaz Khan ◽  
Muhammad Rashid Mirza ◽  
Mirza Nadeem Baig
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Fusion Zone ◽  
Weld Line ◽  
Alloy Sheet ◽  
Inert Gas ◽  
Hardness Profile ◽  
Micro Hardness ◽  
Tungsten Inert Gas Welding ◽  
Zone Width

Pulsed tungsten inert gas welding with full penetration was performed on 1.6 mm thick Ti–5Al–2.5Sn alloy sheet. Hole-drill strain measurement method was employed to measure the distribution of residual stresses across the weld line. Tensile tests were performed on the specimens sectioned in transverse direction of the welded sample. The evolved microstructure in the welded zone was investigated by metallography and X-ray diffraction. Transverse residual stresses of tensile nature were present at different depths below the surface and decreased the yield strength and ultimate tensile strength. However, this decrease was not dependent on the maximum value of transverse residual stress. Fracture location was found to be dependent on the micro-hardness profile and fracture took place in base metal where micro-hardness was the lowest. Furthermore, the presence of tensile residual stresses in the welded sample had no influence on the fractured surface morphology. Peak current and background current had a significant influence on the fusion zone width, heat-affected zone width, and fusion zone grain size.

Influence of electron beam oscillation patterns on the microstructure, texture, residual stress and mechanical properties of Ti-5Al-2.5Sn alloy weldments

2020 ◽  
pp. 095440542093753
Author(s):  
Asim Iltaf ◽  
Massab Junaid ◽  
Fahd Nawaz Khan ◽  
Nabi Bakhsh ◽  
Muftooh Ur Rehman
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Residual Stresses ◽  
Fusion Zone ◽  
Electron Beam Welding ◽  
Physical Phenomenon ◽  
Weld Zone ◽  
Rectangular Pattern ◽  
Rectangular Waveform ◽  
Beam Oscillation

Vacuum electron beam welding is widely employed for the welding of titanium alloys using different beam oscillation patterns. Since these patterns influence the physical phenomenon in the weld pool, its effect on the microstructure, texture, mechanical properties and residual stresses is of prime interest. In order to understand this influence, electron beam welding was used to prepare Ti-5Al-2.5Sn weldments using beam oscillations of triangular and rectangular waveform. It was observed that a change of welding pattern had a strong influence on the residual stresses, impact properties and texture of weld zone while tensile properties were not significantly affected. A partial martensitic transformation was observed in both the triangular and rectangular waveform of oscillations. An increase in alpha lathe width was observed in the fusion zone and similar strength of the rectangular pattern as compared to triangular pattern. Despite of this, the observed higher Vickers hardness of the fusion zone of rectangular pattern as compared to triangular and no-oscillation was attributed to texture strengthening using rectangular waveform.

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