Phase formation in Ti/Ni dissimilar welds

Chatterjee, Subhradeep; Abinandanan, T.A.; Chattopadhyay, K.

doi:10.1016/j.msea.2007.12.041

Cited by 54 publications

(26 citation statements)

References 29 publications

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“…As shown in Figure 4, the weld pools displayed a certain asymmetry and a greater extent of melting was observed on Ti6Al4V skin. This is because the thermal diffusivity of Ti alloy is lower than Ni alloy, resulting in localized heating and greater melting of Ti6Al4V during welding [9]. Moreover, the color of the Ti6Al4V base metal remained consistent for all samples, whereas color variation was observed on the Inconel 600 base metal from one sample to another, as indicated in Figure 4.…”

Section: Metallurgical Characterizationmentioning

confidence: 95%

“…Due to the differences in thermal diffusivity and conductivity, Ti from Ti6Al4V flowed towards the weld pool and reacted with Ni from Inconel. This resulted in inhomogeneous molten flow (Ti-rich melt pool) and asymmetric heat transfer during the welding process, contributing to the formation of these intermetallic phases due to metallurgical dissimilarity as shown in the phase diagram of Ti-Ni [9]. NiTi is reportedly being more erosion-resistant than stainless steels [27,28].…”

Section: Metallurgical Characterizationmentioning

confidence: 99%

“…The XRD analysis indicated that NiTi and NiTi2 formed in the FZ and HAZ. The NiTi2 phase is not recommended in large quantities, because it can lead to a strong tendency of hot cracking, which is prone to cause weaker joints [9,15,16,29]. From Figure 8 it can be seen that the high-temperature B2 phase (austenite) from NiTi was found in samples L2 and L3, which further changed to low-temperature B19' phase (martensite) when the overlapping factor was 30% for sample L1, and the welding speed increased to 50 mm/s for sample L4.…”

Section: Microstructural Observation and Elemental Composition Analysmentioning

confidence: 99%

“…The weld geometry pattern is produced by the differences in dG/dT and it influences the surface tension of the molten pool. Second, inhomogeneous molten flow leads to the phase formation of different crystals due to metallurgical differences [9]. Intermetallic layers are present for dissimilar metal welding due to the differences in thermo-physical properties of the materials.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Influence of the Overlapping Factor and Welding Speed on T-Joint Welding of Ti6Al4V and Inconel 600 Using Low-Power Fiber Laser

Janasekaran

Tan

Yusof

et al. 2016

Metals

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Double-sided laser beam welding of skin-stringer joints is an established method for many applications. However, in certain cases with limited accessibility, single-sided laser beam joining is considered. In the present study, single-sided welding of titanium alloy Ti6Al4V and nickel-based alloy Inconel 600 in a T-joint configuration was carried out using continuous-wave (CW), low-power Ytterbium (Yb)-fiber laser. The influence of the overlapping factor and welding speed of the laser beam on weld morphology and properties was investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. XRD analysis revealed the presence of intermetallic layers containing NiTi and NiTi 2 at the skin-stringer joint. The strength of the joints was evaluated using pull testing, while the hardness of the joints was analyzed using Vickers hardness measurement at the base metal (BM), fusion zone (FZ) and heat-affected zone (HAZ). The results showed that the highest force needed to break the samples apart was approximately 150 N at a laser welding power of 250 W, welding speed of 40 mm/s and overlapping factor of 50%. During low-power single-sided laser welding, the properties of the T-joints were affected by the overlapping factor and laser welding speed.

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Section: Metallurgical Characterizationmentioning

confidence: 95%

Section: Metallurgical Characterizationmentioning

confidence: 99%

Section: Microstructural Observation and Elemental Composition Analysmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of the Overlapping Factor and Welding Speed on T-Joint Welding of Ti6Al4V and Inconel 600 Using Low-Power Fiber Laser

Janasekaran

Tan

Yusof

et al. 2016

Metals

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“…Laser welding is one of the best alternative methods which can overcome the above mentioned problem. Laser welding can also be used for welding dissimilar materials [3][4][5]. Laser welding is a process, in which a highly coherent and monochromatic beam of laser is made to fall upon a narrow area where weld is required.…”

Section: Introductionmentioning

confidence: 99%

Modelling and Characterization of Laser Welded Incoloy 800 Ht Joints

Sathiya¹,

Srirangan²

2016

Adv. Sci. Technol. Res. J.

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This study aims at finding the effect of laser welding speed on incoloy 800 HT. This alloy is one of the potential materials for Generation IV nuclear plants. Laser welding has several advantages over arc welding such as low fusion zone, low heat input and concentrated heat intensity. Three different welding speeds were chosen and CO 2 laser welding was performed. 2D modeling and simulation were done using ANSYS 15 to find out the temperature distribution at different welding speeds and it was found that an increase in the welding speed decreased the temperature. Mechanical properties such as tensile strength, toughness and hardness were evaluated. The effect of welding speed on metallurgical characteristics was studied using optical microscopy (OM), Scanning Electron Microscopy (SEM) with EDS, X-Ray Diffraction (XRD) technique and fractographic analysis. From the results it was found that high welding speed (1400 mm/min) decreased the joint strength. The M23C6 and Ni3Ti carbides were formed in a discrete chain and in a globular form along the grain boundaries of the weld region which increased the strength of the grain boundaries. Fractographic evaluations of the tested specimens for welding speed (1000 and 1200) mm/min showed deep and wide dimples indicating ductile failures.

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