To address the pressing energy and environmental challenges and accelerate the realization of the “Carbon Net Zero” concept, the role of Environmentally Benign Automotive Lightweighting is crucial. Among the various technologies available, automotive lightweighting technologies not only contribute to the “Carbon Net Zero” process, but also extend the range of electric and hybrid-powered vehicles. Moreover, the implementation of environmentally-friendly technologies greatly improves the safety and overall performance of automobiles. The advancement of lightweighting technologies has led to the adoption of novel materials like advanced high-strength steels (AHSS), aluminum and magnesium alloys, fiber-reinforced polymers, and hybrid metal-polymer composites. These materials, combined with innovative structures such as architected cellular structures, and advancements in forming and joining processes, have propelled the field forward.

We organized this Feature Topic and expect it will promote the development of environmentally benign automotive lightweighting technologies and contribute to the “Carbon Net Zero” process. We would also like to take this opportunity to commemorate the Honorary and Founding Executive Editor-in-Chief Professor Fangwu (Mike) Ma for his contributions to eco-driving and for his dedicated support in the publication of the previous Special Issue on Automotive Lightweight in 2020 (https://link.springer.com/journal/42154/volumes-and-issues/3-3).

This Feature Topic comprises eight papers that showcase the latest advances in the pursuit of lightweighting in automotive applications. The core contributions of these articles are summarized below.

1 Highlights of Articles in the Feature Topic

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    The paper titled “Environmentally Responsible Lightweight Passenger Vehicle Design and Manufacturing” by Glenn S. Daehn et al. addresses the urgent challenges of climate change and greenhouse gas emissions in personal transportation. It explores a comprehensive approach to significantly reduce greenhouse gas emissions by emphasizing longevity, utilization, shared ownership, lightweight design, aerodynamic efficiency, comfort, and electric power. This innovative model has the potential to revolutionize automotive manufacturing by reducing material consumption and enhancing per-mile efficiency.

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    The paper “Hybrid Additive Manufacturing of Forming Tools” by A. Erman Tekkaya et al. showcases the integration of additive manufacturing (AM) with classical forming technologies. It presents three applications demonstrating the advantages of AM, including reduced temperatures, increased production speed, complex geometries, lower carbon footprint, and enhanced efficiency in the hot stamping process. This study highlights the potential of hybrid additive manufacturing in advancing tooling design for various forming applications.

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    The paper “Low-Carbon-Emission Hot Stamping: A Review from the Perspectives of Steel Grade, Heating Process, and Part Design” by Junying Min et al. provides an overview of advancements in hot stamping technology, with a focus on carbon emission reduction in the automotive industry. It discusses steel grades, heating processes, and part design techniques that promote material efficiency and lightweighting. This review offers valuable guidance for sustainable hot stamping solutions to researchers, engineers, and policymakers.

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    The paper “Mechanical Performance Evaluation of Multi-Point Clinch-Adhesive Joints of Aluminum Alloy A5052-H34 and High-Strength Steel JSC780” by Yunwu Ma et al. investigates the influence of the clinching process on adhesive layer performance in joining high-strength steel and aluminum alloy. The study examines stack-up orientations and clinching points, identifying factors affecting bonding strength. Valuable insights for optimizing clinch-adhesive joint performance are provided, contributing to the development of efficient and reliable joining techniques for vehicle body manufacturing.

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    The paper “Soft Sensors for Property-Controlled Multi-Stage Press Hardening of 22MnB5” by Juri Martschin et al. presents the development of two soft sensors for measuring and controlling product properties during multi-stage press hardening. These sensors enable feedback control and optimization of product properties, such as temperature distribution and phase fractions. They offer significant potential for improving the efficiency and accuracy of multi-stage press hardening processes.

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    The paper “Non-Associated and Non-Quadratic Characteristics in Plastic Anisotropy of Automotive Lightweight Sheet Metals” by Myoung-Gyu Lee et al. investigates the plastic behavior of lightweight sheet metals using a non-associated flow rule approach. The study highlights the importance of considering non-quadratic characteristics in plasticity modeling, particularly for aluminum alloys, and provides valuable insights for accurate finite element analysis of lightweight sheet metals in automotive applications.

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    The paper “Review of Crashworthiness Studies on Cellular Structures” by Ying Zhao et al. offers a comprehensive overview of innovative cellular structures for energy absorption in vehicle collisions. The review discusses different application forms, design concepts, and manufacturing techniques, emphasizing the exceptional crashworthiness and potential for improving vehicle safety and energy efficiency. It also identifies key challenges in the field and provides valuable guidelines for researchers and engineers working on lightweight cellular structures.

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    The paper “Analysis and Suppression of End Flare in AHSS Roll-Formed Seat Rail” by Dayong Li et al. addresses the issue of end flare, a shape error affecting the forming accuracy of roll-formed parts, using advanced high-strength steel (AHSS). The study analyzes the mechanism of end flare, develops finite element models to predict its occurrence, and proposes effective strategies for its mitigation. The findings highlight the primary factors causing end flare, the benefits of multiple bending processes, and the positive impact of homogenizing longitudinal residual stress on dimensional accuracy.

The collective insights presented in these eight papers contribute to the advancement of environmentally benign automotive lightweighting. We extend our sincere appreciation to all the authors, reviewers, and editors of Automotive Innovation for their dedicated efforts in bringing this Feature Topic to fruition. We hope that this compilation of research stimulates scientific ideas, encourages further exploration, and fosters impactful research in the field of automotive lightweighting.