Listing of projects awarded funding by LightMAT, along with abstracts, links to Annual Merit Reviews, publications, and other relevant information.

NTESS, as manager and operator of Sandia National Laboratories (&quot;NTESS&quot;), UT-Battelle, LLC, as manager and operator of Oak Ridge National Laboratory (&quot;UT-Battelle&quot;), and Battelle, as manager and operator of Pacific Northwest National Laboratory (&quot;Battelle&quot;), (collectively &quot;Contractors&quot;), will collaborate with Mallinda LLC to characterize microscopic structural defects and evaluate the high-speed impact on the company&#39;s malleable thennoset Carbon-Fiber Reinforced Plastic (CFRP) technology.Validating and adopting this special and emerging class of lightweight materials will be critical to reducing the overall weight of on-highway vehicles, as well as ultimately increasing fuel efficiency — while still meeting consumer performance demands.

Leo Fifield

Pacific Northwest National Laboratory

Sandia National Laboratories

Oak Ridge National Laboratory

Continuous-Fiber, Malleable Thermoset Composites with Sub-1-Minute Dwell Times: Validation of Impact Performance and Evaluation of the Efficacy of the Compression Forming Process

This is a two-year effort and PNNL will perform characterization and test magnesium sheet samples and joint assemblies provided by Magna International Inc. The goal of this work is to provide feedback to Magna International Inc. regarding the strength and corrosion behavior and the observed corrosion mechanisms in the joint assemblies. Such feedback will help Magna International Inc. and its partners optimize their joining and corrosion-protection strategies to enable strong structural joints while simultaneously mitigating corrosion and achieving acceptable cosmetic surface finish. In Year I, the focus will be on testing the as-received sheets (baseline) and similar (Mg-Mg) joints while dissimilar joints (Mg-X) will be tested in Year II. The corrosion tests to be performed on various samples/joints include atmospheric corrosion test (SAE J2334) and salt spray/fog test (ASTM B117). Microstructure of the baseline sheets and at the joint interfaces will be analyzed using analytical techniques such as SEM, TEM, EDS, APT, XPS and SIMS. The strength of the joint interface will be evaluated using indentation techniques and tensile testing.

Aashish Rohatgi

Low-Cost Corrosion Protection for Magnesium

There is not currently a viable, cost competitive alternative to cast iron brake rotors for the automotive market. While in past years many weight savings materials and designs have come to other parts of the vehicle, the brake assembly remains tied to near fifty year old technology.Metal matrix composites (MMCs) present an opportunity to replace cast iron brakes in certain vehicles. By replacing cast iron rotors with lighter weight MMCs there is an opportunity to reduce the unsprung weight of the brake assembly and adjacent components such as suspension arms and springs and rotational mass of the rotor itself.Up to this point MMCs have not achieved widespread use. Recent Arconic improvements to the TiB2 production process may make it a more viable technical ceramic for MMCs than in the past. We propose utilizing Titanium Diboride (TiB2) as a substitute for the more tradition MMC efforts with Silicon Carbide (SiC) in an effort to improve performance, wear life, and cost.Arconic will produce master alloys of A356 with 50 volume percent TiB2. These ingots will be used to produce melts with various TiB2 contents from 5 to 20 vol% TiB2, and cast into subscale rotor disks using unique melt-mixing equipment at PNNL. The cast rotors will be machined to subscale rotor configuration and tested on an instrumented Brake dynamometer at PNNL for wear and friction characteristics. The data will be compared to commercial products to demonstrate the advantages over current systems.

Glenn Grant

Metal-Matrix Composite Brakes Using Titanium Diboride

In this project, Magna International Inc. will team with the Pacific Northwest National Laboratory (PNNL) to fabricate a non-RE Mg bumper beam using Shear Assisted Processing and Extrusion (ShAPE™); a new technology developed by PNNL over the past few years. Use of the ShAPE™ process will enable bumper beams with sufficient strength, ductility and energy absorption properties without the need for costly rare earth additives and elevated temperature processing. The non-RE Mg bumper beam will be fabricated by first extruding rectangular profile via ShAPE™ room temperature processing, in a single operation. Post extrusion processing, the profile will be trimmed to length and stretch-bent into a curved bumper beam. A magnesium alloy bumper beam offers a 35% weight savings compared to aluminum alloys and 60% compared to high strength steels. The bumper beam was chosen as the first component to target because the geometry can have a fairly simple 2.5mm cross sectional wall thickness, generally compatible with the PNNL’s knowledge base and equipment capability surrounding ShAPE™. The bumper component offers commercial value by providing mass reduction in the front of the vehicle, providing ride and handling benefit, in addition to mass reduction.PNNL has demonstrated the ability to ShAPE™ process non-RE Mg tubing with high strength, ductility and energy absorption. It has been shown that ShAPE™ extruded ZK60 and Mg2Si tubing with 7.5 mm and 0.75 mm wall thickness have similar energy absorption to AA6061-T6. This is due to significant grain refinement, breakdown and dispersion of second phases and the ability to eliminate anisotropy in compressive and tensile strength by aligning texture 45 degrees to the extrusion axis. Scalability of the ShAPE™ process has been demonstrated in ZK60 by fabricating 50 mm OD tubing with 1.5 mm and 3.0 mm wall thicknesses having concentricity as tight as 1.3%. These tubes exhibit an ultimate tensile strength of 260-300 MPa and room temperature ductility of &gt;20% parallel, perpendicular and 45 degrees to the extrusion axis.For this project, Magna International Inc. will design the bumper beam geometry and PNNL will develop the die set and process parameters to fabricate the desired cross section. Microstructural analysis and mechanical property testing of the extrusions will be performed by PNNL. Magna International Inc. will perform component level mechanical testing to evaluate performance and validate the design model.

Scott Whalen

Non-Rare Earth Magnesium Bumper Beams

We propose to lower the cost penalty inherent in the use of primary aluminum alloys and address mechanical properties issues in Al castings produced by secondary alloys by a two-pronged approach: <ul class="MuiTypography-root MuiTypography-body1"><li>Use an ultrasonics-based technique to modify the size and distribution of the deleterious intermetallics common in secondary aluminum alloys during the solidification process. </li>
<li>Use PNNL-developed novel heat-treatment technique to lower the temperature and/or shorten the heat-treatment duration post-solidification processing in both primary and secondary aluminum alloys.</li>
</ul>

Overcoming the Barriers to Lightweighting by Enabling Low-Cost and High-Performance Structural Automotive Aluminum Castings

Unlike traditional resistance spot welds comprised of the same material, dissimilar Al-Steel resistance spot welded joints form a weld button only in the aluminum sheet while the steel sheet forms a heat affected zone but does not melt. Differences in heat input, joint geometry, sheet thickness, sheet deformation, and microstructural features have all been observed to impact mechanical properties. Furthermore, there are significant differences in the intermetallic compound (IMC) development between joints containing AA6XXX vs AA5XXX and, in general, peak fracture loads can vary by an order of magnitude for a given material stack-up depending upon whether the joint fractures interfacially or via button pullout. However, it is currently unclear specifically which factors are most critical for predicting joint fracture modes in these unique joints comprised of dissimilar aluminum and steel metals. This uncertainty translates to significant development time required when expanding this technology to additional combinations of alloys and sheet thicknesses. This project proposes leveraging unique PNNL capabilities, experience and approaches including measuring localized material properties to develop a predictive model of dissimilar metallic spot joints and their behavior during fracture; specifically, whether the joint fractures via interfacial fracture or button pull-out as a function of alloy, sheet thickness, faying interface microstructure, and thermal-mechanical treatment of the weld nugget and heat affected zone. Having the ability to model whether a given joint structure would fracture interfacially or via button pullout is conservatively estimated to provide a 25% reduction in development time, thus yielding for a given vehicle program an overall savings of 33 FTEs. This would provide a significant step function improvement in reducing the time-to-market for this multi-material, weight-saving technology. This multi-material joint fracture prediction approach can be further applied to the aerospace, marine, defense, and consumer appliance industries with products or components that require the stiffness of steel but also the lightweight, ductile nature of aluminum, and should be able to be extended to other dissimilar material combinations such as aluminum/magnesium or magnesium/steel.

Chris Smith

Prediction of Aluminum/Steel Joint Failure

Diversitak, a company based in Detroit, MI, developed a proprietary, low specific gravity, carbon fiber-reinforced epoxy (CFRE) under U.S. patent number 9,963,58832. Preliminary testing on this new material conducted in collaboration with ArcelorMittal Steel Company proved the CFRE concept. A thin layer of this CFRE was applied to a stamped sheet of steel with residual stamping oils from a mill, in a time corresponding to automotive processing (e.g. ~15 seconds), and processed following automotive e-coat procedures (phosphating + 175–200°C heating), to complete the curing. No problems with adherence or performance were noted. While the CFRE added weight to a thin gauge steel panel, it weighs much less than what is displaced by using thicker conventional mild steel gauges. The application of the coating showed significantly increased dent resistance, oil canning resistance, and part stiffness.This two-year project was designed to mature this new technology to near manufacturing readiness to reduce the weight of a vehicle and lower the cost of weight reduction. The process involved the use of thinner gauge steels than are currently used. The collaborative development team included two industrial manufacturers: Diversitak and ArcelorMittal Steel Company; LightMAT; and two National Laboratories: Oak Ridge National Laboratory (ORNL) and Idaho National Laboratory (INL). The team developed a new manufacturing process to reduce the weight of a vehicle and lower the cost of weight reduction, as well as a better understanding of how to apply the coating so that it performed to a in service high standard. The team also performed an in-depth study to determine the long-term durability of the materials manufactured using this technology and well-known automotive industry standard tests.The overall process involved stiffening the thinner gauge steel by applying the CFRE on only one side. To accomplish this goal, the optimal reinforcement fiber length and fiber concentration was first determined. This was followed by measuring the coefficient of thermal expansion (CTE) in all three directions, so it could be fed into manufacturing models and methods for rapidly and inexpensively applying the coating. This was followed by panel level evaluations of the coating and steel combination, and then by full part demonstration of the technology on door panels. The final step was corrosion testing of the parts.ArcelorMittal characterized the advanced high strength steel (AHSS) (e.g. metallurgy-heat treatment for required AHSS properties as a function of the sheet thickness, state of internal stress) and quantified CFRE adhesion to the steel as a function of sheet preparation (e.g. rolling and stamping).ORNL optimized the fiber length, fiber concentration, and coating thickness for the best vehicle function and performance at the least cost. Along with the suppliers, ORNL developed a durable CFRE application process (e.g. gun material, design, robotic dispensing process) and identified the adhesion stability of the CFRE during process holding. An approach to ensure that application/curing timing conforms to conventional assembly line speed and plant cycle times was determined. ORNL also determined the CTE of the material in all three directions and performed material scanning electron microscopy (SEM) analyses.INL characterized the corrosion properties of the steel panels coated with CFRE. The panels were investigated for corrosion resistance and stability as replacement materials used in automotive body panels to reduce mass. The coupons tested at INL were supplied by Diversitak after an optimized CFRE formulation was achieved in the already coated form for corrosion testing.Based on the extensive testing and understanding of the micronized carbon fiber usage in epoxy formulations leads to optimized product development. Advantages are in low shrinkage properties during cure cycle and composite material adhesion with oily steel surfaces. The carbon fiber optimization studies of length and loading levels were determined based on flexural strength from the ORNL SEM and CTE studies. The optimum levels are 100 µm – 150 µm and at 15% by weight of the formulation. Optimum flexural strength was achieved at these fiber lengths. Longer fibers or increased volume fraction did not show any advantage in strength. In fact, as the fiber length approached 400 µm, the CFRE coating became riddled with voids. Also, for robotic application and viscosity control, the 100 µm size was optimal in terms of uniform coating application.The dent resistance and stiffness factors were shown to have significant improvements ranging from a 25% to 70% increase based on CFRE thickness and location on the panel. The oil canning resistance improved for thin gauge steel with a wider area of application of CFRE at 0.5 mm thickness vs localized application of CFRE.No corrosion occurred when the CFRE coating was intact on any of the coupons tested. However, minimal corrosion could occur if a cut were to exist on a coated surface and exposed to a corrosive enviroment. Even when this occurred, only minimal corrosion was observed with creep or peel back of the CFRE coating, which was not detrimental to the structural performance of the coating. No significant physical degradation of the CFRE coating occurred as a result of environmental exposures (as exemplified by the lap shear and flexurals strenght tests results) over the time periods tested. Extensive corrosion and environmental exposure tests at INL show the robust durability requirements of the automotive OEMs were met and are expected to be met on the full-size production size components.Overall, the LightMAT project met the goals of panel weight reduction of up to 15% with significant improvements in dent and oil canning resistance with proven durability (corrosion) requirements.The corrosion test data clearly shows long-term durability on the panels contrary to the belief that carbon fiber can initiate corrosion. The product technology can help in economically feasible light weight steel parts design eliminating oil canning, improving stiffness and dent resistance. In several ways, the product is compatible with the automotive assembly processes with automation, performance consistency, and durability.Key enablers in panel design are the use of thinner gauge high strength steel without read-through on to a class A surface with the flexibility of applying material robotically; either locally or to large areas on the panel, depending on the requirements.

Gabriel Ilevbare

Idaho National Laboratory

Reducing Mass of Steel Auto Bodies Using Thin, Advanced High-Strength Steel with Carbon-Fiber Reinforced Epoxy Coating

Magnesium (Mg) alloy die-castings are increasingly used in the automobile industry to achieve cost-effective mass reduction, especially in systems where multiple components can be integrated into a single thin wall die casting. However, there are several component quality restrictions in thin-walled Mg die-castings, including variability in dimensional accuracy, part-to-part variation in mechanical properties, and porosity in the final part, which has limited the continued growth of die-cast components in the automobile industry. An alternative to die-casting is the process of thixomolding. While the die-casting process relies on filling a mold at high speeds with the alloy being in the completely molten state, the thixomolding process fills a mold with a thixotropic alloy in a semi-solid slurry state at a temperature between the liquidus and solidus temperatures. Ideally, the material should be ~30–65% solid rather than being completely liquid at the beginning of the injection process. Advantages of the thixomolding process over die-casting include a finer grain structure, lower porosity, improved dimensional accuracy, improved part-to-part consistency, improved mechanical properties (particularly ductility in the component), the ability to reduce wall thickness for mass savings, and longer tool life due to lower process temperatures. The objectives of this project which is a CRADA between Oak Ridge National Laboratory, FCA US LLC, and Leggera Technologies are to develop one or more novel Mg alloys more suitable for the thixomolding process with the potential improved room temperature strength and ductility when compared to current die-casting alloys while achieving components with low volume fraction of porosity. The team will develop the alloys, scale promising alloy/s and fabricate prototype component using the new alloy, and evaluate properties of the material when fabricated into the component.

G. Muralidharan

FCA-ORNL CRADA Final Technical Report, 2023

Development of a Novel Magnesium Alloy for Thixomolding of Automotive Components

This project is focused on advancing additive manufacturing technology for light weight metal alloys. Argonne will utilize its high-energy x-ray capabilities to conduct in-situ experiments mimicking a laser powder bed fusion (LPBF) process. During these experiments high-speed x-ray imaging, thermal imaging, and x-ray diffraction analysis will be used to monitor melt pool dynamics, powder ejection, solidification, phase transformation, and defect formation. This information will be used to better understand the printing parameters and selection parameters that will minimize defect formation. The data generated will also be used for validating computational material models, CALculation of PHAse Diagram (CALPHAD), to be used for designing new lightweight alloys for additive manufacturing.

Aaron Greco

Argonne National Laboratory

Laser Powder Bed Fusion Parameter Development for Novel Steel and Aluminum Powders Using In Situ Synchrotron Imaging and Diffraction

The aim of this work is to modify current steel powertrain materials using small amounts of alloying additions to significantly improve mechanical, physical, and thermal properties of the material. The improved materials will be deployed in Cummins portfolio of light, medium, and heavy-duty diesel engines to enable significantly improved efficiency and weight reduction while maintaining manufacturability and limiting cost increases. The work to be accomplished during this project will include computational design of a series of notional modified alloys, melting and thermo-mechanical processing of the designed alloys, followed by testing and microstructural characterization of the alloys to identify which alloying strategies provide the most optimal performance and cost benefits.

Dean Pierce

Lightweight and Highly-Efficient Engines Through Al and Si Alloying of Martensitic Materials

Lightweight aluminum shape castings have widespread applications for structural components in the automotive, aerospace, and general engineering industries because of their excellent castability, corrosion resistance and particularly high strength-to-weight ratio in the heat-treated condition. In the automotive industry, cast aluminum alloys have been increasingly used to replace cast iron and steel in vehicle applications such as engine blocks, cylinder heads, intake manifolds, brackets, housings, chassis, transmission parts, and suspension systems to reduce mass. As many of aluminum shape castings used in automobiles involve cyclic loading, fatigue properties of the castings are critical to their success. The increasing use of lightweight aluminum cast components in critical structures thus requires improved integrity, with more reliable and quantifiable performance. The objective of this project is to demonstrate and further develop GM’s patent pending, novel casting process, “Pressure-Assistant Precision Sand Casting (PAPSC) for producing flawless cast aluminum cylinder heads with minimum manufacturing and energy costs”. The approach is to leverage NETL’s experience in producing high quality metal castings through various microstructure control and defect elimination technologies as well as comprehensive quantification of microstructure characteristics and mechanical properties. A baseline (production) alloy together with the melt treatment will be initially evaluated with the new PAPSC process to develop and validate the process window for producing flawless cast aluminum heads.

Paul Jablonski

National Energy Technology Laboratory

General Motors-NETL CRADA Final Technical Report, 2024

New Technologies for High-Performance Lightweight Aluminum Castings

Shear Assisted Processing and Extrusion (ShAPE) will be developed to manufacture non-circular multicell profiles using feedstock comprised of magnesium and secondary aluminum. The project will include integration of a porthole extrusion die within the rotating ShAPE process developed by PNNL. The complexity of the profile geometry will be advanced over the course of the project from round to square, to asymmetric trapezoidal, to two-cell asymmetric trapezoidal. Aluminum alloy 6063 in the form of briquettes (compacted shred and engineered machined chips) and castings from pre-consumer industrial scrap in both homogenized and non-homogenized form will be evaluated for use as the feedstock. Tensile tests will be conducted and compared at ASTM minimum standard and ASM typical values.

Association of Washington Business Green Manufacturing Award, 2021

R&D 100 Award in the Process/Prototyping Category, 2020

ASM International Advanced Materials & Processes Magazine, July/August 2024

Magna-PNNL CRADA Final Technical Report, 2023

Shear Assisted Processing and Extrusion (ShAPE) of Lightweight Alloys for Automotive Components

The aim of this project is to develop a novel manufacturing technique to produce lightweight car seats by combining AM and conventional techniques. Note that the scope of the project will be limited to the primary structure of the seat assembly. This does not include any electric motors, sensors, actuators or seat coverings that represent the bulk of the seat assembly mass. Instead, this project will focus on the developing AM and over-molding methods that not only apply to seat structures but would also be relevant to a broad range of structural applications across all vehicle sub-systems.

Vlastimil Kunc

A Novel Manufacturing Process of Lightweight Automotive Seats - Integration of Additive Manufacturing and Reinforced Polymer Composite

This project will develop and demonstrate automotive light-weighting of light-duty vehicle wheel supporting knuckles. The overall approach is to topology optimize the design of a knuckle (aka upright) to take advantage of highly complex geometry fabrication made possible by additive manufacturing. The objective is to demonstrate the ability to cost-effectively (&lt; $5/lb-saved) produce an aluminum alloy knuckle with 50% weight savings compared to the 7.5kg average weight of an equivalent cast iron component for a mid-size sedan produced in 2015.

Alex Plotkowski

Automotive Light-weighting using Topology Optimization and Additive Manufacturing for Steering Knuckles

ORNL and ESE Carbon, a subsidiary of ESE Industries, have collaborated on a LightMAT funded project to further develop carbon reinforced composite wheels for commercialization. ESE Industries, headquartered in Atlanta, GA, was established in 2011 to manufacture one product: carbon fiber composite wheels. Current markets are limited to high end sports cars and luxury vehicles. The business plan is to expand first to the automotive and light truck aftermarkets and then to OEMs and heavy trucks. This project focused on materials characterization, modelling, and testing of composite wheels to pass SAE standards. The primary objective of this project is to couple ESE’s existing passenger-car wheel design and manufacturing process with ORNL’s expertise in materials characterization, and composites processing to accelerate the current development phase and the subsequent commercialization phase.

Brian Knouff

Industrialization of Carbon Fiber Composite Wheels for Automobiles and Trucks

Successfully manufacturing automotive body structure made via the sheet metal stamping process depends upon simultaneous consideration of component design, tooling design, stamping process control, and material properties. In many cases, introducing lightweight sheet materials (e.g., aluminum alloys, magnesium alloys, advanced steels) holds the potential to significantly reduce vehicle weight, but challenges the stamping process by introducing materials with inherently less ductility. Successful and repeatable applications require co-developing the stamping process controls with the varying material properties, including formability. During the stamping process, as soon as the forming limit of the sheet is exceeded, the material splits. Controlling process variability to avoid these material splits will enable deployment of less formable, lighter, and stronger materials for stamped automotive components.The purpose of the project is to develop an AI-driven process control algorithm for stamping process. The project will first focus on the development of a prototype using a simplified product geometry, whose tool is referred to in this project as the Kidney Die. The purpose of initiating the development on this relatively simple geometry is to avoid complicating the matters by introducing tool shapes that might limit potential solutions. Phase 1 will focus on developing the overarching methodology for process modeling, data exchange, and artificial intelligence methods by focusing the entire project team on a common reference stamping (Kidney Die tool). Phase 2 will apply the newly developed methodology (from Phase 1) to multiple active stampings that are in production or being prototyped for production at the Participant vehicle original equipment manufacturers (OEMs).

Vincent Paquit

Lightweight Metal Stampings Enabled by Artificial Intelligence and Real-time Process Monitoring

Fairmount Technologies is developing a new metal forming machine intended to produce ultrahigh strength Aluminum Alloy AA 7075 sheets and is seeking to collaborate with PNNL to optimize the production process, as well as the strength and formability of the sheet produced. Results will be used to infer (and optionally demonstrate) whether aluminum components such as side-impact beams can be successfully formed from this sheet.

AA 7075 Sheet with 700 MPa Strength for Automotive Structural Components

Palo Alto Research Center, Inc. and PNNL will develop advanced carbon fiber-reinforced polymer (CFRP) materials and manufacturing process that will equip automotive manufacturers with a scalable innovation that reduces costs, improves performance, and accelerates the deployment of CFRP materials across vehicle classes.

Kevin Simmons

Lightweighting Technology by Enhanced Composite with Fully Recyclable Particles (LiTE CFRP)

This project will develop approaches to overcome the barriers to simultaneous high-strength and high resistance to stress corrosion cracking (SCC) in Al casting alloys. Thus, success in this project will enable fabrication of light-weight components that are otherwise made of either heavier cast iron, or lower-strength Al alloys which need to be oversized (and hence, are heavier) to compensate for lower strength. This project will leverage the availability of advanced analytical instruments and scientific expertise available only through the LightMAT Consortium. If successful, this project has the potential to enable lightweighting of multiple components in light-duty cars and trucks across all makes and models.

Mitigate Stress Corrosion Cracking (SCC) in High-strength Al Castings

Structural battery enclosures must meet the most stringent quality and performance requirement in electric vehicle body structures, including being leak-proof to prevent the battery inside malfunctioning and creating a safety hazard. Since battery enclosures are a key contributor to the weight of a battery system, the third generation (3rd GEN) advanced high-strength steel considered for significant mass savings at affordable cost. However, the 3rd GEN advanced high-strength steel have a propensity for weld cracking, causing leaking through welds. These cracks are difficult to detect with today’s commercial non-destructive evaluation. This project will develop and demonstrate a weld quality diagnostic tool by innovative use of advanced non-destructive evaluation technology powered by machine learning to meet industry’s needs for accurate, reliable, fast, and cost-effective leak inspection of welded battery enclosures.

Dr. Zhili Feng

A Machine Learning Assisted Weld Quality Diagnostic Tool to Assure Structural Integrity of Electric Vehicle Battery Enclosure

Atmospheric pressure plasma deposition using a new, low-energy process was recently demonstrated as a replacement for conversion coatings for surface treatment to bond dissimilar, lightweight materials, offering significant cost savings and elimination of chemical waste. The system shows potential to overcome limitations of existing commercial systems in the chemical bonding and structures that can be produced. The proposed work is aimed at establishing the capabilities of the new process, improving the robustness for manufacturing, and evaluating alternative precursors for expanding the surface characteristics and performance for different lightweight materials. The advanced surface characterization capabilities and expertise at Pacific Northwest National Laboratory will be leveraged to develop the fundamental understanding needed to accelerate the path to implementation in manufacturing.

Atmospheric Plasma Deposition for Adhesive Bonding of Multi-Material Systems

Ultra-large aluminum (Al) castings are increasingly used in critical automotive applications to reduce number of parts and production lead time, and especially to reduce mass, energy, and tooling cost. Associated challenges include the use of high fractions of costly primary Al to achieve ductility, potential high casting scrap rates due to increased geometric complexity, and increasing uncertainty of material properties and component performance. This project will develop a new cast Al alloy with greater sustainability (larger fractions of secondary Al) and robust high-integrity die casting process for high-performance, ultra-large castings. The project will apply integrated computational materials engineering tools and leverage national laboratory advanced experimental capabilities to accelerate alloy development, culminating in demonstration of a large rear rail casting with 42 percent mass reduction.

Development of Sustainable Aluminum Alloy for Lightweight Ultra-Large Castings

Carbon fiber composites have attracted considerable attention due to the potential for substantial mass savings, with many examples now implemented in the low volume luxury car market. However, migration to higher volume applications has been hindered by: (a) high material cost, (b) high processing times, and (c) perception of low sustainability. This project will address all three of these barriers: (a) carbon fiber material to replace aluminum in structural components at a cost penalty of no more than $5/Kg-saved (aka weight buy); (b) fitting into high-speed auto process, like injection molding; and (c) end-to-end sustainable material based on post-industrial waste carbon fiber and nylon 66, and the ability to recycle end-of-life auto parts. The opportunity lies in combining DowAksa USA LLC capabilities in carbon fiber manufacturing and resin chemistry intermediate production with the unique testing capabilities inherent within Pacific Northwest National Laboratory.

Wholly Sustainable, Cost-Effective Carbon Fiber-Nylon Compounds

Magnesium (Mg) alloys, due to their high specific strength and abundant presence, have been considered for applications in automobile industry for light-weighting for decades, and some successful examples have been reported. However, their wide application is still limited due to the low corrosion resistance of existing Mg alloys. Although surface coating may be one of the solutions, it complicates the process with adding cost. Recent study in literature shed some light on the possibility to significantly improve the corrosion resistance of Mg. This project will develop new Mg alloys with increased corrosion resistance for electric vehicle by leveraging the capabilities of national laboratory in integrated computational material engineering (ICME), alloy design and advanced experiments.

Sumit Bahl

Development of Sustainable High Corrosion Resistant Magnesium Alloy for Drive Unit Housing Assembly in Battery Electrical Vehicles

Structural battery enclosure must meet the stringent quality and performance requirement in EV body structures, including leak-proof to prevent the battery inside malfunctioning and safety hazard. Since battery enclosure is a key contributor to the weight of battery system, high strength lightweight Al alloys are considered for significant lightweighting at affordable cost. But these Al alloys are prone to weld solidification cracking, causing leaking. This project will develop an advanced high-speed laser welding process through process innovation assisted by advanced welding simulation to ensure cracking free laser welding of lightweight EV battery enclosures to meet industry’s needs for fast and cost-effective battery enclosure assembly under the high-volume production environment.

Ensure Laser Welding Quality through Process Innovation Assisted by Advanced Welding Simulation in Lightweight EV Battery Enclosures

Advanced lightweight materials, including multi-phase steels, aluminum extrusions and aluminum castings, have increasingly replaced mild steel to meet original equipment manufacturer (OEM) demand for increased fuel economy and crash-safety requirements. Third Generation (Gen 3) AHSS provides a superior combination of strength and ductility for crash energy management components in the vehicle body-in-white (BIW). Aluminum extrusions are widely used for bumper, door rocker panel, cradle and battery frame applications. Aluminum castings are increasingly being used in electric vehicles to provide part consolidation, weight saving and increased driving range. Rocker panels are, for example, an important component of the battery electric vehicle (BEV) body structure. The rocker panel serves several purposes, including structural support, crash resistance, protection for the vehicle&#39;s underbody and battery tray, and contributing to the overall aesthetics. In order to reduce weight, rocker panels are usually constructed using outer panels consisting of 3rd generation advanced high strength steels (AHSS) and an inner multicell aluminum extrusion structure for energy absorption which protects the batteries in a crash event. It is well known, however, that these material combinations provide significant challenges for joining and are susceptible to liquid metal embrittlement and loss of strength. The overall goal is to find a solution that addresses these challenges in order to produce multi-material vehicle components with reduced weight and minimal galvanic and recyclability issues. The approach being proposed here is to utilize a novel high velocity (HiVe) riveting and clinching technique recently demonstrated by Pacific Northwest National Laboratory (PNNL) to join (2T/3T) sheets of aluminum alloys and steel. This process will not only address the aforementioned challenges, but also help significantly reduce the joining cycle time. This work will also demonstrate use of HiVe assemblies to be retrofitted to existing body-shop robots thus having minimal impact to existing body shop operations.

Vineet Joshi

High Velocity Joining of Multi-material Stacks Containing 3rd Generation Advanced High-Strength Stainless Steel and Aluminum Extrusion and Casting

The rapid deployment of battery electric vehicles (BEV) is transforming the light-duty transportation landscape. Improvements in energy density and reduced powertrain cost have enabled an increasing rate of deployment of BEVs. However, this rapid deployment has relied mainly on traditional manufacturing process and techniques, that are not optimal for BEV production. This CRADA team is poised to address one of these shortcomings through an advanced multi-material processing technology called PrintCast developed at the Oak Ridge National Laboratory (ORNL).This team is targeting scale up of advanced lightweight materials for the battery enclosure as a needed area for technology improvement and associated vehicle efficiency improvements through mass reduction in battery electric vehicles. According to the EPA’s light duty trends report, the average weight of a conventional internal combustion engine (ICE) vehicle in 2021 was 1945 Kg. However, the average BEV weighs nearly 33% more than conventional ICE counterparts, with an average of 2472 Kg. The specific mass increase of a BEV reduces range, increases energy usage, and increases negative externalities like particulate matter emissions from tires and brakes. The upper end of this CRADA teams’ estimation is that if fully deployed PrintCast approaches to BEVs (battery containment structures, multi-material joining, thermal management, and future body-in-white optimization) offer an impressive weight reduction up to 600 Kg per BEV.This CRADA team will address one of the largest opportunities for BEV weight reduction, the battery enclosure. By demonstrating PrintCast advantages for weight reduction, crash protection/energy absorption, and thermal management in. this single component, we calculate that for an light-duty BEV a 175Kg weight savings (7% of total vehicle weight) will be realized, as compared to the existing enclosure.

Derek Splitter

PrintCast Approach for Ultra-Lightweighting of Battery Electric Vehicle Battery Enclosures

Awarded Projects

These are the projects awarded funding by LightMAT, listed by year.