Advanced Joining Technologies for Automotive Lightweight Structures: Fundamental Investigations
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Shaping and Forming Committee
Program Organizers: Yan Huang, Brunel University London; Carla Barbatti, Constellium

Monday 2:00 PM
March 20, 2023
Room: 29C
Location: SDCC

Session Chair: Shouxun Ji, Brunel University London


2:00 PM  
A Novel Approach for In-process Monitoring of Dissimilar Ultrasonic Welds of Multi-strand Aluminum Wires and Copper Terminals Utilizing the Seebeck Effect: Andreas Gester1; Toni Sprigode1; Guntram Wagner1; 1Chemnitz University of Technology
    Industrial process monitoring during ultrasonic metal welding of automotive wires and terminals often encompasses sample-based destructive tensile testing as well as the surveillance of welding parameters. Monitoring of all joints down to lot size one and the avoidance of false-positives is not possible with these options, leading to large amounts of pseudo-rejects and undetected faulty welds. However, the increasing substitution of copper wires with light-weight aluminum in automotive wire harnesses, resulting in dissimilar joints of aluminum wires and copper terminals, enables monitoring of other physical properties. Current work focusses on a novel approach for utilizing the thermoelectric effect for process monitoring. In this paper the actual measurement setup is presented and a setup for industrial use is proposed. In order to quantify the correlation between thermoelectric properties, joint strength and the welding parameters previously used for process monitoring Pearson correlation coefficients were determined for all values.

2:25 PM  
Microstructure and Mechanical Properties of Electron Beam Welded AA2024 to AA6061 Dissimilar Joints: Jyotirmaya Kar1; 1Malaviya National Institute of Technology Jaipur
    Similar/dissimilar aluminum alloy joints find extensive applications in the aerospace and automotive sector. During welding, formation of porosities is a major challenge as it significantly hampers mechanical properties. Besides, hot-cracking, alloying element loss, and atmospheric contaminations are few added issues during fusion welding. For aluminum alloy joining, the electron beam welding (EBW) process is gaining popularity. However, reports on effect of different EBW processing conditions on weld characteristics of aluminum alloys are limited. For this study, dissimilar butt-joints of AA2024 to AA6061 were produced using different EBW conditions like varying welding speed, number of weld passes, and beam oscillation patterns. The joints were subjected to porosity and microstructure analysis and mechanical property evaluations. It was observed that for certain optimized processing conditions 60-85% reduction in weld porosity content occurs. Microstructure became more homogenous and mechanical properties (Charpy and fatigue) improved with an increase in welding speed or oscillating beam joints.

2:50 PM  
Numerical Analysis of High-Velocity Riveted (HVR) Joints through Finite Element Modeling Supported by Experimental Data: Daniel Ramirez Tamayo1; Lei Li1; Benjamin Schuessler1; Vineet Joshi1; Ayoub Soulami1; 1Pacific Northwest National Laboratories
    High-Velocity Riveting (HVR) is a novel joining method that allows the joining of two sheets of metal through a metallurgical bond resulting from the high-speed impact with the rivet and the die. Different combinations of Aluminum Alloys (AA6061-T6, AA7075-T6, and AA5052) were joined using HVR and resulted in lap-shear joint performance outperforming conventional riveting, clinching, and adhesive bonding. We present a 3D finite element (FE) model used to help inform the die design and processing conditions. The model was able to simulate the joining process and results at the interface between the joined sheets suggested that high pressures and temperatures lead to joints with superior performance. Model findings in terms of joint cross-sections, and lap-shear performance are in good agreement with the experiments. Parametric studies on rivet material, rivet shape, and die design were conducted and analyzed to inform the process development and achieve high-quality joints.

3:15 PM  
Recent Advances in the Transformative Non-fusion Weld-brazing Process Used to Join Thin-gauge Alloys Used in the Automotive Industry: M. Shehryar Khan1; Yong Hwan Cho1; Frank Goodwin2; Y. Norman Zhou1; 1University of Waterloo; 2International Zinc Association
    As we rapidly move towards the electrification of modern vehicles, making them lighter and stronger has become as important as ever. This means that the welding and joining techniques we use to build automotive structures need to evolve to be able to successfully join the advanced materials used for these applications. Weld-brazing (WB) is a novel non-fusion joining technique that has shown excellent promise in the joining of similar and dissimilar metallic alloys. However, existing literature on WB has either treated this process as a form of traditional torch brazing or a form of fusion welding which has made the optimization of the process a significant challenge. Researchers at the University of Waterloo have shown that WB is a joining technique that is fundamentally different from the traditional joining techniques it has been derived from. This study investigates recently discovered critical factors that control the joint integrity for WB applications.