High Strength Aluminium Sheet Metal Joining by Resistance Spot Welding

2013 ◽  
Vol 765 ◽  
pp. 761-765 ◽  
Author(s):  
Rudolf Gradinger ◽  
Nikolay Sotirov ◽  
Gottfried Rettenbacher ◽  
Christoph Pangerl ◽  
Philipp Dörner ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Spot Welding ◽  
Elevated Temperatures ◽  
Stable Process ◽  
High Strength ◽  
Automotive Body ◽  
Aerospace Applications ◽  
Joining Technology ◽  
Body In White ◽  
Opening Up

Aluminium AA7075 is well known as extrusions, plate or sheet metal predominately in aerospace applications. The continuing efforts for reducing the weight but still maintaining the safety of vehicle structures are opening up the way for this alloy in automotive applications. Since this branch is very different to space as well as aircraft industries in manufacturing methods, costs and production numbers, the development of appropriate processes is necessary. After showing a high potential for deep drawing of AA7075 sheets under elevated temperatures, the joining technology options are now under investigation too. Since spot welding is very common in automotive body-in-white manufacturing, an innovative version of this process is evaluated for applicability for welding AA7075-T6 sheets to each other and to proven automotive aluminium alloys. The results of sample weldments, including mechanical static strength, micrographs, hardness, radiography and parameters for a stable process range, are presented.

scholarly journals Specimen's Geometry Related Influences on Load-Bearing Capacity of Joining Aluminium and UHSS by Innovative Shear-Clinching

2017 ◽  
Vol 6 (4) ◽  
pp. 19 ◽  
Author(s):  
Rejane Horhold ◽  
Martin Muller ◽  
Marion Merklein ◽  
Gerson Meschut
Keyword(s):  
Lightweight Design ◽  
High Strength ◽  
Single Step ◽  
Economic Conditions ◽  
Automotive Body ◽  
Joining Technology ◽  
Strength Capacity ◽  
Body In White ◽  
Design Requirements ◽  
Manganese Steels

Economic conditions as well as comfort and safety-related requirements lead to lightweight design especially in automotive body-in-white production processes. The consequential multi-material mix limits the reliability of conventional thermal joining technologies. Innovative mechanical joining technologies need to be established. Following the lightweight-design requirements, next step for weight-reduction would be the renunciation of additional elements. Clinching technologies support this idea by creating a form- and force-fitting joint, but are limited to the formability of the joining partners. Joining by forming without additional elements even of hot formed ultra-high-strength manganese steels and ductile aluminium can be realised by shear-clinching. A precisely coordinated tool setup initialises a crack in the die-sided material with limited formability without harming the punch-sided ductile aluminium. This paper presents current and detailed investigations of the influences of mechanical loads on strength capacity of multi-material joints using shear-clinching technologies. The results clearly show the promising potential and challenges of this innovative single-step joining technology for multi-material mixes.

Process Feasibility Analysis of Self-Pierce Riveting High Strength Low Alloy Steel

2010 ◽  
Author(s):  
L. Han ◽  
M. Thornton ◽  
R. Hewitt ◽  
A. Chrysanthou ◽  
M. Shergold
Keyword(s):  
Spot Welding ◽  
Hsla Steel ◽  
Sheet Material ◽  
Dissimilar Materials ◽  
High Strength ◽  
Feasibility Analysis ◽  
Low Alloy Steel ◽  
Automotive Body ◽  
Body In White ◽  
Selection Of

Self-Piercing Riveting (SPR) has been widely used in automotive Body in White (BIW) assembly as an alternative to Resistance Spot Welding (RSW), in particular for joining of dissimilar materials, for example Steels to Aluminium. A study examining the process feasibility of SPR of Aluminium alloy AA5754 and High Strength Low Alloy (HSLA) steel in various thicknesses has been conducted. It has been shown that the process is capable of joining the two materials together. However, it was also observed that the selection of rivet and die is limited when joining HSLA. The setting force required to drive the rivet into the sheet material to be joined tends to be high. This leads to potential tooling life concerns. It was also shown that the arrangement of the high strength steel joined to aluminium can have a significant effect on the process feasibility.

Optimizing spot welding parameters in a sheet metal assembly by neural networks and genetic algorithm

2007 ◽  
Vol 221 (7) ◽  
pp. 1175-1184 ◽  
Author(s):  
M Hamedi ◽  
M Shariatpanahi ◽  
A Mansourzadeh
Keyword(s):  
Neural Networks ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
The Body ◽  
Welding Parameters ◽  
Automotive Body ◽  
Body In White ◽  
Assembly Operations

Deformation of the spot-welded sub-assemblies in assembly operations and the gap between the matching sub-assemblies have been quality concerns specifically in the automotive industry. Overall quality of the car body and its sub-assemblies, apart from quality of each stamped part, depends markedly on the welding process. This paper considers optimization of three important process parameters in the spot welding of the body components, namely welding current, welding time, and gun force. In this research, first the effects of these parameters on deformation of the sub-assemblies are experimentally investigated. Then neural networks and multi-objective genetic algorithms are utilized to select the optimum values of welding parameters that yield the least values of dimensional deviations in the sub-assemblies. Welding sub-assemblies with the optimized set of parameters brought all of them into the tolerance range. The proposed approach can be utilized in manufacturing sub-assemblies that can fit and match better with adjacent parts in the automotive body. It enhances quality of the joint and will result in improving overall quality of the body in white.

Sheet Metal Forming - A New Kind of Forge for the Future

2007 ◽  
Vol 344 ◽  
pp. 9-20 ◽  
Author(s):  
Manfred Geiger ◽  
Marion Merklein
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Elevated Temperatures ◽  
High Strength ◽  
Light Weight ◽  
Influencing Parameters ◽  
General Possibility ◽  
Industrial Relevance ◽  
Weight Structures

Within the last years in sheet metal forming a trend towards forming at elevated temperatures as well as temperature assisted forming technologies can be observed. This development is caused by the increasing need on light and high strength materials in order to fulfill the demands of light weight structures. The decision which kind of temperature assistance is the most useful in order to improve the formability of the material depends on a hugh number of process influencing parameters, like e.g. the material itself, the geometry of the component, the number of forming operations etc.. In this paper the general possibility to separate different temperature assisted forming processes with regard to the used materials will be introduced. The different forming procedures will be explained and discussed. Examples with an industrial relevance are shown.

Experimental Study on the Crash Performance of Aluminum and Steel Rails

2002 ◽  
Author(s):  
Chelliah Madasamy ◽  
Omar Faruque ◽  
Tau Tyan
Keyword(s):  
Mild Steel ◽  
Energy Absorption ◽  
Sheet Metal ◽  
High Strength Steel ◽  
High Strength ◽  
Maximum Load ◽  
Design Parameters ◽  
Impact Speed ◽  
Automotive Body ◽  
Metal Thickness

Increasing government mandated CAFE´ standards are forcing the OEMs to aggressively reduce vehicle weight. Aluminum, with a density of about a third of that of steel, has been established as a viable alternative to steel for the construction of the automotive body structure. However, for aluminum sheet metals, there are still lingering concerns about the reliability and robustness of the available joining techniques such as spot-welding, riveting etc. The investigation reported in this paper was aimed at evaluating the relative performance of self-pierced riveted aluminum rails as compared to spot-welded mild steel and high strength steel rails. A series of straight and curved (S-shaped) rails made of aluminum, mild steel, and high strength steel have been tested. Other design parameters considered in this study include sheet metal thickness, rivet/weld location, rivet/weld spacing, adhesives, temperature, and impact speed. As were observed from the tests, axial crush mode dominated the deformation of all straight rails while bending dominated the deformation of the curved rails. Statistical analysis was performed to find the relative importance and effects of each variable on the average crush load, maximum load and energy absorption. For aluminum rails, the thickness of the sheet metal was found to be the primary controlling factor for both straight and S-rails. Other factors i.e. rivet spacing/location, adhesives, temperature and impact speed, had no significant affect on the performance of the rails. For the steel rails, the sheet metal thickness, impact speed, temperature and material properties, were all found to be significant for the crash behavior. It was also found that the aluminum rails have higher specific energy absorption than the steel rails confirming that aluminum as a material is more efficient in absorbing crush energy than steel.

Comparative study on CO2 laser overlap welding and resistance spot welding for automotive body in white

2015 ◽  
Vol 78 ◽  
pp. 107-117 ◽  
Author(s):  
Lifang Mei ◽  
Dongbing Yan ◽  
Genyu Chen ◽  
Dang Xie ◽  
Mingjun Zhang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Co2 Laser ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Resistance Spot ◽  
Automotive Body ◽  
Body In White

scholarly journals Microstructure and Properties of Spot Welded Joints of Hot-Stamped Ultra-High Strength Steel Used for Automotive Body Structures

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 285 ◽  
Author(s):  
Zhixia Qiao ◽  
Huijun Li ◽  
Lianjin Li ◽  
Xiaoyu Ran ◽  
Liwen Feng
Keyword(s):  
Spot Welding ◽  
Mechanical Performance ◽  
High Strength Steels ◽  
High Hardness ◽  
High Strength ◽  
Resistance Spot ◽  
Automotive Body ◽  
Ultra High Strength Steels ◽  
Structural Parts ◽  
Spot Welded

Hot-stamped ultra-high strength steels have been widely used in automobile structural parts. Considering the high splash tendency in resistance spot welding due to their extremely high hardness, in this work, microstructural characteristics and mechanical performance of the resistance spot welded ultra-high strength steels are investigated. The results indicate that the interface between the nugget and heat-affected zone (HAZ) is the weakest zone where fractures initiate. In tensile shearing tests, a qualified spot welding joint failed with a button-shaped fracture. Welding defects would significantly decrease the load-carrying capacity and lead to interfacial fracture, except for a button-shaped fracture. In spot welding, it was found that a specific mid-frequency alternating current (AC) input mode, in which a 6 ms cooling cycle was inserted between every two neighboring current pulses, can avoid the splash in the spot welding of hot-stamped hardened steels.

Deformation Mechanisms of Ti6Al4V Sheet Material during the Incremental Sheet Forming with Laser Heating

2013 ◽  
Vol 549 ◽  
pp. 372-380 ◽  
Author(s):  
Linda Mosecker ◽  
Alexander Göttmann ◽  
Alireza Saeed-Akbari ◽  
Wolfgang Bleck ◽  
Markus Bambach ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Microstructural Evolution ◽  
Elevated Temperatures ◽  
Sheet Material ◽  
Sheet Thickness ◽  
High Strength ◽  
Local Strain ◽  
Deformation Mechanisms ◽  
Dislocation Glide ◽  
Sheet Metal Parts

ncremental sheet metal forming (ISF) is a suitable process for the production of small batch sizes. Due to the minor tooling effort and low forming forces, ISF enables the production of large components with inexpensive and light machine set-ups. Hence, ISF is an interesting manufacturing technique for aeronautical applications. Sheet metal parts in aircrafts are often made of titanium and its alloys like the high strength alloy Ti Grade5 (Ti6Al4V). The characteristic low formability of Ti6Al4V at room temperature requires forming operations on this material to be carried out at the elevated temperatures. The interaction of heating and deformation cycles results in a microstructure evolution, which is believed to have a high impact on formability and product quality. In the present work, the temperature-dependent microstructural evolution of the as-deformed parts was investigated. Longitudinal pockets with different depths were formed using a laser-assisted ISF process. The microstructural evolution and hardening of the material were analyzed with respect to the local strain in different forming depths and pocket zones. The formability of the material together with the deformation depth and the sheet thickness-reduction were found to be strongly dependent on the applied process temperatures and the activated deformation mechanisms like dislocation glide and dynamic recrystallization.

Sign in / Sign up

Export Citation Format

Share Document