Microstructure and residual stresses in Ti-6Al-4V alloy pulsed and unpulsed TIG welds

Mehdi, Brahim; Badji, Riad; Ji, Vincent; Allili, B.; Bradai, Djamel; Deschaux-Beaume, Frédéric; Soulié, Fabien

doi:10.1016/j.jmatprotec.2016.01.018

Cited by 82 publications

(41 citation statements)

References 24 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When the average hardness levels of samples joined using different welding speeds-i.e., different heat input, were examined, it was found that the hardness of the weld metal and HAZ was higher than for the base metal (Figure 9). The reason for this outcome has been reported to be the formation of harder and finer acicular α martensite structures in the weld metal and HAZ, compared to the structure of the α + β base metal [28,29]. Hardness level was observed to decrease as either laser power increased or welding speed decreased; i.e., as heat input increased.…”

Section: Microhardnessmentioning

confidence: 95%

“…Hardness level was observed to decrease as either laser power increased or welding speed decreased; i.e., as heat input increased. Investigators reported that hardness levels decreased as a result of coarsened primary β structure due to higher heat input [29]. With lower heat input, on the other hand, an increase in hardness is expected, owing to the formation of finer-grained α structures [23].…”

Section: Microhardnessmentioning

confidence: 99%

See 1 more Smart Citation

Robotic Nd:YAG Fiber Laser Welding of Ti-6Al-4V Alloy

Köse

Karaca

2017

Metals

View full text Add to dashboard Cite

Abstract:In the present study, Ti6Al4V titanium alloy plates were joined using a robotic fiber laser welding method. The laser welding process was carried out at two different welding speeds. Effects of different heat input conditions on the microstructure and mechanical properties of robotic fiber laser welded joints were investigated. Some grain coarsening was observed in the microstructure of weld metal in samples joined using high heat input, compared to those using low heat input, and volume rates of primary α structures increased in the weld metal. The microstructure of weld metal in samples joined using low heat input was made of basket-weave or acicular α' grains and primary β grains in grain boundaries. Tensile and yield strength of samples joined using low heat input were higher than for those joined using high heat input, but their ductility was lower.

show abstract

Section: Microhardnessmentioning

confidence: 95%

Section: Microhardnessmentioning

confidence: 99%

Robotic Nd:YAG Fiber Laser Welding of Ti-6Al-4V Alloy

Köse

Karaca

2017

Metals

View full text Add to dashboard Cite

show abstract

“…Sundaresan et al (1999) reported that pulsing of the welding current in TIG welding can also be used for grain refinement in the fusion zone (FZ) of some ␣-␤ titanium alloys. The recently published work of Mehdi et al (2016) reported that pulsed TIG welding of Ti-6Al-4V led to a decrease in tensile residual stresses as compared to un-pulsed TIG welding. According to Firm et al (1994), the resistance to stress corrosion cracking of Ti-5Al-2.5Sn is less than other titanium alloys because of the presence of Sn and Al which promote the formation of Ti 3 Al structures.…”

Section: Introductionmentioning

confidence: 98%

A comparative study of pulsed laser and pulsed TIG welding of Ti-5Al-2.5Sn titanium alloy sheet

Junaid

Baig²,

Shamir³

et al. 2017

Journal of Materials Processing Technology

View full text Add to dashboard Cite

Pulsed Nd:YAG laser beam welding (P-LBW) and pulsed tungsten inert gas (P-TIG) welding were used to prepare full penetration bead-on-plate weldments of 1.6 mm thick Ti-5Al-2.5Sn alpha titanium alloy sheet. The influence of welding phenomenon on the microstructure, micro-hardness, tensile properties, surface and sub-surface residual stress distribution and deformation and distortion of both the weldments were studied. Higher cooling rate in P-LBW resulted in complete ␣' martensitic transformation in fusion zone whereas in P-TIG weldment ␣' and acicular ␣ was formed within equiaxed ␤ matrix due to lower cooling rate. Hardness in fusion zone of P-LBW was higher than that of the fusion zone of P-TIG weldment due to faster cooling rate in P-LBW. The welded zone in both the weldments showed higher hardness and strength than that of the parent metal since a ductile fracture occurred in the un-welded section during tensile testing. Residual stresses in both P-LBW and P-TIG weldments showed similar trend but the distribution was much narrower in P-LBW due to less width of heat affected zone. P-LBW resulted in more nonuniformity in through thickness stress profile because of greater top to bottom width ratio. Less residual stresses, deformation and distortion and superior mechanical properties in P-LBW made the process more feasible than P-TIG for the welding of Ti-5Al-2.5Sn alloy sheet.

show abstract

“…A review of literature suggests that the peak current, background current and welding speed are the three critical factors in P-TIG welding process [16][17][18][19] . The upper and lower limits of the critical factors are identified based on initial experimentation.…”

Section: Experimental Workmentioning

confidence: 99%

Response surface approach to minimize the residual stresses in full penetration pulsed TIG weldments of Ti-5Al-2.5Sn alloy

Khan

Junaid

Baig³

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

Pulsation of current in tungsten inert gas (TIG) welding is employed to obtain good quality weldments. Peak current, background current, and welding speed in TIG welding are important parameters and their effects on the induced residual stresses are studied using Box–Behnken design methodology. The location of maximum residual stress was found to be close to the weld centerline. Longitudinal and transverse residual stresses at this location were found to be dependent on the pulsed TIG welding input parameters. However, using design of experiment approach, welding speed was found to have the most dominant influence on the stress values. In order to minimize the residual stresses, a reduction in heat input also led to reduction of weld pool penetration. The results of multiresponse optimization showed that in order to achieve a full penetration weldment, a minimum value of 235 MPa for longitudinal and 84 MPa for transverse residual stress will be attained. A weldment with these features can be obtained by using a high value of peak current and a high value of welding speed.

show abstract

Microstructure and residual stresses in Ti-6Al-4V alloy pulsed and unpulsed TIG welds

Cited by 82 publications

References 24 publications

Robotic Nd:YAG Fiber Laser Welding of Ti-6Al-4V Alloy

Robotic Nd:YAG Fiber Laser Welding of Ti-6Al-4V Alloy

A comparative study of pulsed laser and pulsed TIG welding of Ti-5Al-2.5Sn titanium alloy sheet

Response surface approach to minimize the residual stresses in full penetration pulsed TIG weldments of Ti-5Al-2.5Sn alloy

Contact Info

Product

Resources

About