To advance sustainable initiatives and technologies, we partner with customers, academic institutions and other public and private entities. Here are some highlights of our recent work.
Bonding over adhesives
Vehicle manufacturers want to use combinations of high-strength steel, aluminum, magnesium, carbon-fiber composites and other lightweight materials to reduce vehicle mass and improve fuel economy. This approach requires new adhesive chemistries that will mitigate corrosion and thermal expansion issues associated with joining dissimilar materials.
To assist these customers, we are collaborating with Lawrence Livermore National Laboratory and Pacific Northwest National Laboratory. The project is supported by the High Performance Computing for Manufacturing (HPC4Mfg) program, which is funded by the U.S. Department of Energy (DOE) Vehicle Technologies Office.
The project is using supercomputing to fundamentally understand how new adhesives will perform over their lifetimes. Such a model will be used to quickly narrow down many new adhesive options to identify the best candidates that are capable of passing months or years of required lab testing.
Electrocoat performance prediction
We are collaborating with Ford Motor Company and Brigham Young University to better understand the early stages of the electrodeposition process. This ultimately will help reduce the time and expense of testing electrocoat (e-coat) performance on new vehicles and parts.
We introduced the first automotive body cathodic e-coat system in the 1970s, and it is one of the key reasons that cars no longer rust out. The process involves dipping car parts or complete car bodies into a bath of e-coat paint and then using an electrical charge to deposit paint on every conductive surface. The e-coat continues to deposit until all exposed metal is protected.
The first study, completed in 2019, provides a better understanding of the chemical and electrical mechanisms at work during the initial e-coat deposition. This enables our team of researchers to use improved computer simulation models to more efficiently design new electrocoat products.
Going with the flow
With the paint shop typically consuming 70% of an automotive assembly plant’s energy, we are always seeking technical advances to reduce the amount of energy consumed per car painted.
Most cars are painted using robotic arms fitted with electrostatic rotary spray bells to efficiently atomize paint, with the bell spinning at 25,000 to 70,000 revolutions per minute. Through centrifugal forces, paint pumped to the bell is broken up into the tiny droplets that give a car its smooth, glossy appearance. The challenge is that the faster paint is pumped through the bell, the bigger the droplets and the lower the quality of the paint job.
Through the DOE’s HPC4Mfg program, we are collaborating with Berkeley Lab’s Computational Research Division to understand the key mechanisms driving the atomization process on an electrostatic bell. The goal is to reduce energy consumed per car by increasing paint flow rates without reducing process quality.
Using the cutting-edge atomization model developed under the program, our researchers can easily experiment to find out which specific properties will optimize paint atomization and then design paint to that specification.
The curing balance
Curing a coated automotive part that combines lightweight composite and aluminum materials requires the right balance of time, temperature and preparation to deliver the desired results.
To find that balance, we partnered with Ford Motor Company and Ohio State University to perform research and development with support from the DOE Vehicle Technologies Office. Our work included adapting existing coating technologies for lightweight materials, developing a new adhesive formulation, and testing the performance of the coating and adhesive at the lower bake temperatures required when using these mixed-material assemblies.
Ford is now evaluating the coated test parts that combine carbon fiber reinforced polymer (CFRP) and aluminum. The parts were cured about 25 C cooler than the normal process.
As part of the project, Ohio State also conducted corrosion science research that will advance the auto industry's knowledge of how implementing CFRP in a multi-material car body affects the corrosion performance.