Numerical modelling and experimental validation of the effect of laser beam defocusing on process optimization during fiber laser welding of automotive press-hardened steels

Khan, M. Shehryar; Shahabad, Shahriar Imani; Yavuz, Mustafa; Duley, W. W.; Biro, E.; Zhou, Y.

doi:10.1016/j.jmapro.2021.05.006

Cited by 61 publications

(17 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…), the surface roughness that will change the reflection, scattering and transparency of the sample and the duration of exposure to the laser beam. [ 12–17 ]…”

Section: Introductionmentioning

confidence: 99%

“…They may reach several tens of kW for continuous lasers to up to several PW for pulsed lasers. [ 18 ] Lasers may thus generate high temperatures in a sample with an extreme spatial and temporal precision and are therefore commonly used in material sciences for surface cleaning, [ 12 ] material cutting, [ 13 ] engraving, [ 14 ] welding, [ 15 ] sintering [ 16 ] or in medicine for surgery, [ 17 ] i.e., many applications for which the local heating created by the laser is advantageous. On the contrary, when lasers are used to probe a sample as in Raman spectroscopy or fluorescence microscopy, the associated increase of temperature may alter the sample.…”

Section: Introductionmentioning

confidence: 99%

“…), the surface roughness that will change the reflection, scattering and transparency of the sample and the duration of exposure to the laser beam. [12][13][14][15][16][17] All these parameters have thus to be considered during micro-Raman spectroscopy analysis.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Influence of laser shape on thermal increase during micro‐Raman spectroscopy analyses

Foucher

2021

J Raman Spectroscopy

View full text Add to dashboard Cite

Micro-Raman spectrometers are used in various domains, from archaeology to space exploration. These systems use microscope objectives to focus the laser onto the sample to be analysed. Although this method drastically increases the spatial resolution down to a few hundreds of nanometres, it is also commonly admitted that this focused laser beam may heat and alter the studied material.The setting of the laser power is thus a universal problem for any micro-Raman spectroscopy user who has to find a compromise between the Raman signal intensity and the risk of thermal alteration. This parameter is not easy to set based on bibliographic references because, depending on the architecture of the system used, on the laser wavelength and on the sample, damage may occur at very different laser power levels. Here, we describe the different parameters that influence thermal increase induced by the laser and propose easy to make experiments to measure them. A series of experiments is then carried out to study the thermal alteration of various materials when exposed to a laser beam focused with the different microscope objectives of a micro-Raman system. It is shown that, except for very thin samples or powdered materials, the relevant parameters to consider are the laser power at the sample surface and the duration of exposure to the laser beam, whatever the objective used. We also demonstrate that the risk of sample alteration is almost non-existent for thick transparent materials. Interestingly, it is shown that, for semi-transparent materials, alteration may occur at lower laser power for low magnification objectives than for high magnification objectives. These results are explained by the high aperture angle of microscope objectives which induces high dispersion of the laser within the sample.

show abstract

“…), the surface roughness that will change the reflection, scattering and transparency of the sample and the duration of exposure to the laser beam. [ 12–17 ]…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of laser shape on thermal increase during micro‐Raman spectroscopy analyses

Foucher

2021

J Raman Spectroscopy

View full text Add to dashboard Cite

show abstract

“…Moreover, the final appearance of the areas adjacent to the weld seam should be investigated since violent spurts of the molten Al-Si coating ejected from the weld pool have been observed with the application of the graphite coating. Other interesting approaches consist in enlarging the laser spot on the workpiece surface through beam defocusing [43], the use of optics with higher focal length [44], with particular beam modules, e.g., collateral dual-beam module [45], or with a laser beam oscillation [46,47]. In addition, a characteristic Y-shaped weld section, instead of the common X-shaped (or hourglass-shaped) FZ, could be achieved through beam defocusing [43] or setting the process parameters in the narrow range of values that allows to weld in the particular closed (or blind) keyhole condition [48,49].…”

Section: Introductionmentioning

confidence: 99%

Laser welding of tailored blanks made of Al-Si-coated 22MnB5 steel using a filler wire and a variable energy distribution laser optics

Coviello

Heydt²,

Rullo³

et al. 2023

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Laser welding of Al-Si-coated steels for hot stamping in automotive applications is problematic due to the mixing of the coating layers inside the molten pool that weakens the resulting weld seam. In this case, the most common welding procedure to overcome this issue consists in removing the Al-Si layer through laser ablation prior to the joining. This method continues to be the most widely used by major producers of tailor welded blanks, although in situ ablation of the Al-Si coating can be costly and time consuming. In this work, a novel approach consisting in joining as-received (i.e., not decoated) materials using a filler wire and an innovative variable energy distribution laser optics is introduced and tested on tailor welded blanks made of 22MnB5. Tensile tests of specimens obtained from a 33 full factorial design of experiment have shown an average value of ultimate tensile strength of 1523 MPa, which is much higher than the one usually observed in as-received welded then hot-stamped conditions and aligned with hot-stamped base material values. Hardness test results (494–543 HV0.5) were in the typical hot-stamped base material range of values as well, while SEM–EDS analyses detected no ferrite inclusions inside the fusion zone. Variations of the main process parameters have been considered on an iso-thickness and iso-material configuration, empirically demonstrating the stability and reliability of the proposed methodology as well as its suitability for production purposes.

show abstract

“…Westerbaan et al 26 investigated the performance of the welds with a special focus on the impacts of concavity on the fatigue resistance for automotive steels. Stephens et al 27 predicted the fatigue life at critical areas on the HMMWV military vehicle under variable amplitude load by using the numerical method and the hot‐spot stress approach.…”

Section: Introductionmentioning

confidence: 99%

Fatigue performance investigation on the automotive welded structure under damped loads using the Taguchi method

et al. 2022

View full text Add to dashboard Cite

In the present paper, a three-dimensional numerical model has been built using ANSYS code to analyze the static and fatigue behavior of a welded design based on four rectangular profiles under damped loads for automotive application. The fatigue of the proposed design is generally influenced by a number of factors. The aim of this study is to investigate the effect of the load level, the stress ratio, the mean stress theory, the geometry size, the weld bead height, the temperature of the weld bead on the durability (P 1 ), and the

show abstract

Numerical modelling and experimental validation of the effect of laser beam defocusing on process optimization during fiber laser welding of automotive press-hardened steels

Cited by 61 publications

References 24 publications

Influence of laser shape on thermal increase during micro‐Raman spectroscopy analyses

Influence of laser shape on thermal increase during micro‐Raman spectroscopy analyses

Laser welding of tailored blanks made of Al-Si-coated 22MnB5 steel using a filler wire and a variable energy distribution laser optics

Fatigue performance investigation on the automotive welded structure under damped loads using the Taguchi method

Contact Info

Product

Resources

About