Above: Jaguar Land Rover has an aluminum closed-loop strategy by recycling the metal in order to transform the vehicles of today into the cars of tomorrow

April 2023- THE VEHICLE SUPPLY CHAIN IS LIVING IN THE FAST LANE

If you think the switch to having microprocessors operate every function of a motor car was disruptive and transformative, the electrification of the world’s commercial and consumer fleets is becoming much more so, according to experts in automotive and metals manufacturing. The industry is pressing forward in “engineering new business models to support an inexorable transition to connected, autonomous, shared and electric (CASE) technologies —especially electric vehicles (EVs),” according to a recent report by four automotive analysts at PwC US (Brian Decker, Paul Carrannanto, Akshay Singh and Kunal Arora). “It’s a lot to manage. Both original equipment manufacturers and suppliers learned hard lessons from the pandemic lockdowns and global microchip shortage about building resiliency into their operations and business models.” The authors say that the EV transition “will accelerate beyond 2030. OEMs will likely have committed about $500 billion (and counting) in manufacturing investments over the next decade to help jumpstart the large-scale shift to EVs.” The number of EV-only manufacturing plants in the United States alone is expected to rise from nine today to 41 in 2029, according to PwC. “The EV components sector is poised for significant growth, with U.S. electric powertrains and batteries expected to hit $128 billion by 2035, up from $10 billion in 2021.

“We can expect an overall investment momentum that should … shift from the vast majority of vehicles being powered by internal combustion engines to the majority being electric vehicles. By 2029, auto OEMs globally are forecast to launch over 1,000 BEV nameplates, with North America accounting for about 170, the consultancy forecasts. Modern Metals has quizzed automotive experts at both the Aluminum Association and the American Iron and Steel Institute about how this transition is rippling out to design changes and new product creation.

ALUMINUM’S STRENGTHS

The use of aluminum in automotive applications continues to increase, says Blake Zuidema, on behalf of the Aluminum Transportation Group (ATG) and Novelis, citing a Ducker Carlisle study sponsored by the ATG. “In 2022, the average automobile weighed 4,029 pounds. Of that, roughly 501 pounds was aluminum in various forms: extrusions, castings, forgings and sheet. We expect that to grow to 556 pounds by 2030,” he says. Many of the new grades developed over the last few years “are focused on the higher strength applications. There was a concern, driven by UHSS, that aluminum was falling behind. Our industry sought to bring up overall strength levels. “Three grades come to mind,” Zuidema says. “We are developing the Novelis Advanz 6HS – s600 with an in-service strength of 340 MPa; 7UHS – s701 is a 7000-series high-strength aluminum, with tensile strength of up to 520 MPa.” He says that grade was originally developed for the aerospace industry. Novelis and others are also developing T6 and T7 tempers that will allow carmakers to eliminate post-forming heat treatment. “All are expected to provide higher strength. In the specific strength, divided by density, these are at or above the same strength steel alloys.”

      Ford Motor Co.’s F-150 pickup aluminum body

      General Motors Co.’s axle production facility, Grand Rapids, Michigan

ROOM TO GROW

As for applications within the conventional power train, “there has been an expansion beyond hood and doors, with more fenders and a lot more body structure applications,” Zuidema says. “Among the higher-end luxury and sports cars, it is battery enclosures that have the most room to grow.” Major reasons include the pressure from automotive designers “to keep frames as light as possible.” More battery enclosures are being specified in aluminum, he says, and the structures are built from stamped sheet and extrusions.

      Ford’s Chicago Assembly Plant

As platforms shift to BEV from ICE, transmissions, engine blocks and gear exchangers “go away,” and heat exchangers are needed “to get rid of the heat from charging the batteries. We are seeing growth in aluminum in that sector.” Due to the presence of the battery, Zuidema says, protection is needed from side impacts. “So sills and rockers are new opportunities for extruded aluminum and stamped and rolled forms of aluminum.”

       Mercedes-Benz assembly plant, Tuscaloosa, Alabama.

     Attendees at the annual Great Designs in Steel seminar discuss a body in white design.

SAFETY REQUIREMENTS

One of the most important risks to manage with the new EVs is preventing a battery fire. “If a battery shorts out, or it sustains damage from a collision or by kicking something up from the road, you may have to dissipate a lot of energy quickly,” Zuidema explains. The aluminum industry and its supply chain partners have done extensive research and development work on insulation materials, intumescent (fire retardant) paints and coating materials that expand when heating up, he says, “which provides excellent fire protection.” He acknowledges that aluminum remains more expensive to manufacture than steel. However, the aluminum industry sponsored a survey last year looking at cost tradeoffs. “You have two choices when designing a vehicle to get to maximum mileage range more batteries or make the vehicle lighter to go farther with fewer batteries. So which is cheaper? Take weight off? The study found that for large pickups, SUVs and performance cars where acceleration and range was important, it is more cost effective to use aluminum than to use steel. For lighter vehicles, A and B segment cars, the cost dynamics are a bit different,” Zuidema says.

      Producers of automotive materials are always pursuing the best combination of high strength and formability

REGULATORY ENVIRONMENT

The aluminum industry has done a lot to address roadblocks, but many questions remain. For example, “we don’t know where federal emissions regulations will go. There were stringent requirements [under the Obama administration], which were then rolled back [under the Trump administration], and then revived [under Biden].” Bottom line: “The transportation industry is committed to reducing its carbon footprint. We believe this direction will continue.” When recycled, “aluminum is low carbon and that will continue to become more attractive. We are also working on other ways to reduce CO2 in the long-term.”

PLATFORM PIVOT

“There is a tremendous amount of alternative materials” used in manufacturing cars and trucks, many of which bring “unique attributes,” but 50 to 55 percent of the vehicle “will likely remain in steel,” says Chris Kristock, vice president of the automotive program at AISI. “The rapid proliferation of EV designs presents new targets and opportunities for steel’s participation in the automotive market.” These include “removal of the powertrain and internal combustion engines being replaced by new structures and components,” which has pivoted steelmakers’ focus from fuel tanks to battery enclosures. Steel provides the energy absorption and strength to protect battery packs in a collision, Kristock notes. “We are losing the engine block, but the battery pack is a large mass—1,000 pounds or more than in an ICE platform. Some of that additional weight needs to be compensated with new body structure designs to meet vehicle performance targets. Steel will retain a leadership position in material volume,” he predicts.

SUPER STRONG, SUPER HARD

The trend from mild carbon steel grades to high-strength, advanced high-strength and ultra-high strength steel grades (AHSS, UHSS) continues and may garner up to 60 percent of automotive steel vehicle volume by 2030.

“These grades have the attribute of improved formability at very high strength, and that’s crucial to the automotive design and forming process,” says Kristock, because HSS can be cold stamped at commercial quantities. There are families of grades that offer both high strength and even greater formability, he continues. Third-generation steels have reached strengths up to 980 megapascals (MPa). “1180 MPa is heading to commercial scale” and the industry is working to create a grade that has strength levels up to 1470 MPa—“that’s over 200,000 psi for load bearing, a big advantage to steel,” he notes. The industry is also working on press-hardenable steel alloys that are designed to develop parts up to 2000 MPa. “The austenitized material has very high formability and with in-die quenching, we are developing super hard, super strong automotive parts.” That compares with the use today of 1500 MPa hot-stamped grades. Electric steel grades, used in electric motors, require special alloying and high degrees of special rolling, Kristock says. The incumbent domestic producers are developing new grades that offer magnetic permeability and low core loss. He explains, “the orientation of the grain is such that you don’t generate as much heat. Other suppliers are developing their own capabilities to produce similar grades. These absolutely support motor laminations. There has been growth in the quality and available quantity of those steels,” he adds.

LIMITING EMISSIONS

Another development that steel and automotive are partnering on is greenhouse gas emissions reduction. According to Kristock, “Steelmakers in the U.S. have the lowest greenhouse gas emissions intensity of the major steel-producing countries in the world. The American steel industry continues to work to further reduce emissions through rigorous and varied decarbonization strategies. Through the use of lower GHG emissions intensive raw materials and energy sources, automotive steels are produced in the U.S. today that can help automakers achieve their GHG goals throughout their supply chains,” he says. Overall, steel facilities “are being modernized. Billions are being invested. But it’s not a race,” he says, because an unrestrained speed to market will actually counteract good design. Instead, the industry is taking a disciplined approach to EV design solutions. “Automakers are trying to produce vehicles with the right weight, cost and sustainability than were available with previous platforms.” MM

Aluminum Association, 703/358-2960, http://aluminum.org/

Aluminum Transportation Group, http://drivealuminum.org/

American Iron and Steel Institute, 248/945-4777, http://steel.org/