When automotive engineers look to improve the fuel economy of their vehicles, increasing the efficiency of their engines is only half of the equation. Maximizing the number of miles an engine can eke out from one gallon of fuel only goes so far before they have to consider the weight of the car that engine propels. That’s the reason lightweighting has become a major area of interest for vehicle manufacturers; a lighter vehicle burns less fuel than a heavier one to accelerate by the same amount. Lightweighting is simply the process of redesigning vehicles around new materials and assembly methods to decrease their mass without sacrificing performance and safety.
The range of materials any given manufacturer may be interested in varies; current promising candidates include aluminum and magnesium alloys, high-strength steels, and reinforced polymer composites. These materials don’t have to be used in isolation, either; any economically viable lightweighting approach would have to combine materials, creating a need for ways to join them that are secure, resilient, and easy and economical to use.
Through NCMS’ Commercial Technologies for Maintenance Activities (CTMA) Program, NCMS member PPG Industries is currently partnering with Oakland University (OU) to investigate different adhesives to join aluminum, magnesium, and carbon-fiber composite joints. The goal is to develop a structural adhesive that can accommodate expansion due to heat, cure at low temperatures (high temperatures can damage composites), withstand crashes, and endure the long-term stresses caused by normal operation.
According to the Department of Energy, “Using lightweight components and high-efficiency engines enabled by advanced materials in one quarter of the U.S. fleet could save more than 5 billion gallons of fuel annually by 2030.” Reducing a vehicle’s weight by just ten percent can improve its fuel economy by six to eight percent. Using lightweight materials to replace the cast iron and steel in its body and chassis can halve their weight.
Many lightweight materials are already commercially available, and their potential is well-established. What remains to be done is for engineers to figure out how to apply them to build familiar products and platforms, a challenge PPG and OU are tackling head-on.