Dynamics of laser surface texturing in boosting lightweight vehicle design: a study by Seoul National University of Science and Technology

A team of researchers from Seoul National University of Science and Technology has uncovered a promising method to enhance the strength and durability of joints in lightweight vehicle design. By exploring laser surface texturing (LST) techniques on galvannealed advanced high-strength steel (AHSS), this research led by Professor Changkyoo Park, discovered how specific patterns can significantly improve the performance of metal-polymer joints under conditions mimicking real-world stresses, vital for reducing vehicle weight and improving fuel efficiency. This research was available online on November 7, 2024, and subsequently published in Volume 181, Part C of the journal Optics & Laser Technology on February 1, 2025.

“This method provides a breakthrough for joining metal and plastic, two materials traditionally challenging to bond due to differences in their physical properties,” explains Prof. Park. “By grooving different LST patterns on the surface of AHSS and joining it with glass fiber-reinforced polyamide 6 (PA 6) using injection molding, we significantly improved the mechanical interlock and overall strength of the joints.”

The study focused on specific LST patterns, including diagonal and orthogonal designs, which significantly improved resistance to wear and tear and tensile shear strength, achieving up to 78.9 MPa—much higher than traditional automotive structural adhesives that typically achieve around 25 MPa. These patterns effectively improved the mechanical bonding between AHSS and PA 6, a combination that is becoming increasingly important in automotive manufacturing, especially with the industry's shift towards lightweight materials.

Practically, this technique could address a key challenge in the automotive industry: reducing vehicle weight to meet fuel efficiency and emission standards. The study’s findings suggest that optimizing the surface structure of AHSS through LST could lead to stronger, more durable joints with plastic materials, making it easier to incorporate plastics in car parts and reducing overall vehicle weight. This would lead to significant gains in fuel efficiency, and consequently, lower greenhouse gas emissions, aligning with global efforts to make transportation more sustainable.

This advancement has significant real-world applications, including enhancing safety and performance in road driving conditions. “Laser surface texturing is fast and programmable, allowing optimal strength and longevity at any desired joints in the car body and chassis,” says Prof. Park.

“The potential of this research extends beyond automotive applications. By developing more efficient methods for joining different materials, this study opens new avenues for innovation in various industries such as aerospace and shipbuilding, contributing to the global push for greener, more efficient technologies,” Prof. Park concludes.

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Reference

DOI: 10.1016/j.optlastec.2024.112049

About the institute Seoul National University of Science and Technology (SEOULTECH)
Seoul National University of Science and Technology, commonly known as 'SEOULTECH,' is a national university located in Nowon-gu, Seoul, South Korea. Founded in April 1910, around the time of the establishment of the Republic of Korea, SEOULTECH has grown into a large and comprehensive university with a campus size of 504,922 m².

It comprises 10 undergraduate schools, 35 departments, 6 graduate schools, and has an enrollment of approximately 14,595 students.

Website: https://en.seoultech.ac.kr/

About Changkyoo Park
Prof. Changkyoo Park is a Professor in the Department of Materials Science and Engineering at Seoul National University of Science and Technology. His research focuses on laser-material interactions and laser surface treatments. Prof. Park earned his B.S. and M.S. degrees from Korea University in 2009 and 2011, respectively, and completed his Ph.D. in Materials Science and Engineering at The Ohio State University in 2015. Before joining Seoul National University of Science and Technology in 2023, he worked at Samsung Electronics' Semiconductor R&D Center and the Korea Institute of Machinery and Materials.