Details
| Original language | English |
|---|---|
| Article number | 022418 |
| Journal | Journal of Laser Applications |
| Volume | 31 |
| Issue number | 2 |
| Publication status | Published - 1 May 2019 |
| Externally published | Yes |
Abstract
Over the last few decades, the demand for lightweight constructions has been increased continuously for several industrial applications, like automotive and ship building, to reduce the weight of vessels in order to minimize the CO2 emissions as a result of a lower fuel consumption. Lightweight construction is almost applied for ship applications, especially for yachts, which are designed by using aluminum for the deck constructions and steel for the ship hull. For joining these parts, a high-power laser welding process shall be developed. However, the welding of these dissimilar materials is associated with great challenges, due to the different physical properties and the formation of hard and brittle intermetallic phases, which may influence negatively the properties of the weld seam. The quality of dissimilar joints depends strongly on the mixture ratio between the molten amount of steel and aluminum. However, the mixture ratio varies over the weld seam length due to a high dynamic of the keyhole resulted by welding of this material combination. Furthermore, different batches of materials and varied sheet thicknesses t may influence the mixture ratio. In this study, a high-power laser welding process is developed with in-process control of the penetration depth tP by analyzing the spectral process emissions for dissimilar lap joints of aluminum alloy EN AW-6082 (t = 8 mm) and steel S355 (t = 5-7 mm). In the context of these investigations, an increase of occurring cracks within the weld seam and ejections of molten material with increasing penetration depth tP can be observed. To achieve a relative high joint strength, the penetration depth tP must be kept constant at a value of 1.4 mm. In case of varied batch of material, thickness t of the used sheets, welding speed vS, and leap of the steel sheet thickness t, the penetration depth tP requested cannot be achieved. Using the in-process control of the penetration depth tP, the weld seam quality remains almost constantly over the weld seam length, as shown in visual inspections, metallographic analyses, profiles of the penetration depth tP, and tensile shear testing. Among other things, the appearance of ejections of molten material can be avoided by using the in-process control of the penetration depth tP.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics
- Engineering(all)
- Biomedical Engineering
- Physics and Astronomy(all)
- Instrumentation
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In: Journal of Laser Applications, Vol. 31, No. 2, 022418, 01.05.2019.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Investigations on in-process control of penetration depth for high-power laser welding of thick steel-aluminum joints
AU - Lahdo, Rabi
AU - Seffer, Oliver
AU - Kaierle, Stefan
AU - Overmeyer, Ludger
N1 - Funding information: The joint project “Laser Welding of Steel to Aluminum for Applications in Shipbuilding” (LaSAAS) is funded by the German Federal Ministry for Economics and Energy (BMWi) and supervised by the Forschungszentrum Jülich GmbH (PtJ). Furthermore, the authors would like to thank the project partners and the project committee member companies as well as their representatives for supporting the project and for their cooperation.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Over the last few decades, the demand for lightweight constructions has been increased continuously for several industrial applications, like automotive and ship building, to reduce the weight of vessels in order to minimize the CO2 emissions as a result of a lower fuel consumption. Lightweight construction is almost applied for ship applications, especially for yachts, which are designed by using aluminum for the deck constructions and steel for the ship hull. For joining these parts, a high-power laser welding process shall be developed. However, the welding of these dissimilar materials is associated with great challenges, due to the different physical properties and the formation of hard and brittle intermetallic phases, which may influence negatively the properties of the weld seam. The quality of dissimilar joints depends strongly on the mixture ratio between the molten amount of steel and aluminum. However, the mixture ratio varies over the weld seam length due to a high dynamic of the keyhole resulted by welding of this material combination. Furthermore, different batches of materials and varied sheet thicknesses t may influence the mixture ratio. In this study, a high-power laser welding process is developed with in-process control of the penetration depth tP by analyzing the spectral process emissions for dissimilar lap joints of aluminum alloy EN AW-6082 (t = 8 mm) and steel S355 (t = 5-7 mm). In the context of these investigations, an increase of occurring cracks within the weld seam and ejections of molten material with increasing penetration depth tP can be observed. To achieve a relative high joint strength, the penetration depth tP must be kept constant at a value of 1.4 mm. In case of varied batch of material, thickness t of the used sheets, welding speed vS, and leap of the steel sheet thickness t, the penetration depth tP requested cannot be achieved. Using the in-process control of the penetration depth tP, the weld seam quality remains almost constantly over the weld seam length, as shown in visual inspections, metallographic analyses, profiles of the penetration depth tP, and tensile shear testing. Among other things, the appearance of ejections of molten material can be avoided by using the in-process control of the penetration depth tP.
AB - Over the last few decades, the demand for lightweight constructions has been increased continuously for several industrial applications, like automotive and ship building, to reduce the weight of vessels in order to minimize the CO2 emissions as a result of a lower fuel consumption. Lightweight construction is almost applied for ship applications, especially for yachts, which are designed by using aluminum for the deck constructions and steel for the ship hull. For joining these parts, a high-power laser welding process shall be developed. However, the welding of these dissimilar materials is associated with great challenges, due to the different physical properties and the formation of hard and brittle intermetallic phases, which may influence negatively the properties of the weld seam. The quality of dissimilar joints depends strongly on the mixture ratio between the molten amount of steel and aluminum. However, the mixture ratio varies over the weld seam length due to a high dynamic of the keyhole resulted by welding of this material combination. Furthermore, different batches of materials and varied sheet thicknesses t may influence the mixture ratio. In this study, a high-power laser welding process is developed with in-process control of the penetration depth tP by analyzing the spectral process emissions for dissimilar lap joints of aluminum alloy EN AW-6082 (t = 8 mm) and steel S355 (t = 5-7 mm). In the context of these investigations, an increase of occurring cracks within the weld seam and ejections of molten material with increasing penetration depth tP can be observed. To achieve a relative high joint strength, the penetration depth tP must be kept constant at a value of 1.4 mm. In case of varied batch of material, thickness t of the used sheets, welding speed vS, and leap of the steel sheet thickness t, the penetration depth tP requested cannot be achieved. Using the in-process control of the penetration depth tP, the weld seam quality remains almost constantly over the weld seam length, as shown in visual inspections, metallographic analyses, profiles of the penetration depth tP, and tensile shear testing. Among other things, the appearance of ejections of molten material can be avoided by using the in-process control of the penetration depth tP.
UR - http://www.scopus.com/inward/record.url?scp=85065131710&partnerID=8YFLogxK
U2 - 10.2351/1.5096105
DO - 10.2351/1.5096105
M3 - Article
AN - SCOPUS:85065131710
VL - 31
JO - Journal of Laser Applications
JF - Journal of Laser Applications
SN - 1042-346X
IS - 2
M1 - 022418
ER -