Steel is a good choice in combination with composites because it is cost effective for large-scale production, has excellent fire-resistance and OEMs are already familiar with it, adds Armendariz.
When designing the battery enclosure, “we need to be very aware of the parts count and the job each component is doing. When you approach this with the whole picture in mind, you get to choose where you want those joints, where they are least exposed and where they add more value,” he says.
In most cases, Katcon uses both mechanical connections and adhesives in the joints. Although mechanical fastenings add some complexity, Armendariz doesn’t expect that the industry will switch entirely to an adhesive solution anytime soon.
“It’s not just about lightweighting; it’s also being efficient with material allocations, energy utilization and the need to be sustainable. So, the optimal combination is when we use adhesives in combination with other joining methods,” he explains.
In the future, Armendariz expects to see greater use of multi-material components throughout vehicles. “In the end, I think that’s going to help us design better vehicles, grow efficiencies and be more sustainable,” he says.
Better Solutions for Bonding
In 2014, researchers working on a composites technology roadmap for the National Institute of Standards and Technology questioned manufacturers about the areas of research they were most interested in. Finding the best way to join composites with other materials was one of their top three concerns. Established in July 2021 at the Georgia Tech Manufacturing Institute, the Center for Composite and Hybrid Materials Interfacing (CHMI) will research this topic through a five-year, renewable grant from the National Science Foundation’s (NSF) Industry-University Cooperative Research Center (IUCRC) program.
The three universities involved – Georgia Tech, Oakland University in Michigan (OU) and the University of Tennessee, Knoxville (UTK) – will collaborate with members of an industry consortium to develop and disseminate methods, technologies and tools that facilitate rapid, reliable and cost-effective composite and hybrid materials joining and interfacing. CHMI’s goal over the next 10 years is to reduce, by at least 50%, the cost, cycle time and variation of these operations.
Industry input is built into the project. Consortium members vote on which projects to pursue, and they fund the research through their membership fees. In addition, company representatives will serve as mentors to review progress and guide the project research. Each university has a different industry focus – Georgia Tech on aerospace, OU on automotive and UTK on infrastructure and medical devices.