United States: Driven by Material Progress
The lightweighting route of American automobiles is driven by material progress, comprehensively considering material cost, performance, recyclability, and usage. From 2010 to 2025, the tensile strength of high-strength steel will range from 1500 to 2000 MPa, with a 5% decrease in density and a 10% increase in modulus. Aluminum alloy mechanical properties will improve by 40%, costs will decrease by 25%, and high-performance aluminum recycling will reach 50%. Magnesium alloy costs will drop to be comparable to aluminum, availability will increase by 2 times, and electrochemical corrosion between dissimilar materials will be eliminated. Titanium alloy and nickel alloy costs will decrease by 50%, with costs twice that of stainless steel. Carbon fiber will account for 5% of the vehicle’s weight, priced at $5 per pound, with a 30% increase in stiffness, 25% recyclability, and a 25% reduction in carbon footprint.
From 2025 to 2050, the tensile strength of high-strength steel will reach 2500 to 3000 MPa, with a 10% decrease in density and a 20% increase in modulus. Aluminum alloy mechanical properties will improve by 200%, costs will decrease by 40%, and high-performance aluminum recycling will reach 100%. Magnesium alloy costs will be equivalent to steel, availability will increase by 4 times, and universal one-step pretreatment will be adopted. Titanium alloy and nickel alloy costs will decrease to the level of aluminum alloy, with costs 1.5 times that of stainless steel. Carbon fiber will account for 15% to 25% of the vehicle’s weight, priced at $2.5 per pound, with stiffness comparable to aluminum, 50% recyclability, and a 75% reduction in carbon footprint.
The lightweighting route in the United States focuses on reducing material costs and optimizing performance, and the manufacturing of automotive parts in the United States is characterized by comprehensively considering the cost-effectiveness of different materials for application in different parts of the car.
Europe: Targeting Multi-material Application Technology
The lightweighting route of European automobiles starts with the application of three types of advanced lightweight materials: advanced steel materials, light metals such as magnesium and aluminum, and carbon fiber-reinforced composite materials, aiming at multi-material application technology.
The development path of automotive lightweighting in Europe is driven by innovation, focusing on advanced material technology, new modular construction, advanced functional integration, affordability and cost-effectiveness, multi-material connection, multi-material simulation, and multi-material recycling. The development and application process of materials includes: design concept, application of material technology, modeling and simulation, material processing technology, part production, manufacturability and cost analysis, testing and validation, LC analysis, and EL evaluation. The European automotive lightweighting route fully integrates material properties with cost, manufacturing processes, and structural design, achieving lightweighting goals through multi-level and multi-angle coordination.
Japan: Material and Process Utilization
In Japan’s automotive lightweighting approach, breakthroughs in basic research on materials and processes serve as the starting point for practical applications, with material advancements driving lightweighting.
For steel, research focuses on high-rigidity steel materials and nanofiber materials as the foundation, with honeycomb structure materials as the source of investigation. Breakthroughs have been made in high ductility high-strength steel, anisotropic control, and high stamping formability steel plates, leading to the development of high-strength and high-toughness non-quenched and tempered steel.
For aluminum, research is based on high-strength and high-ductility aluminum alloys, with the stiffening of aluminum alloys as the source of study. Breakthroughs have been achieved in porous aluminum composite materials and aluminum wiring harnesses, enabling improvements in stamping forming technology and the utilization of extruded profiles.
Magnesium research focuses on high-strength cold-rolled sheet alloy design technology and high-speed extrusion technology for high-performance profiles. Root research involves microstructure refinement techniques for casting materials. Breakthroughs in high-performance surface treatment for large profiles have led to productive innovation in casting materials.
For composite materials, basic research is conducted on transparent DLC technology, SP-treated nanoparticles, and achievement records, resulting in improvements in SP-treated nanoparticle surface technology.
In processing technology, basic research focuses on the utilization of servo presses and plate forgings. Root research involves net forming technology and intelligent hot stamping. Breakthroughs have been made in CFRP forming and magnesium cold stamping, leading to the development of hollow material forming technology and high-strength steel forming technology. After foundational and root-level breakthroughs in connecting different materials, innovative technologies for connecting metal/polymer/C-FRP three-dimensional shapes have been established.
Since 2010, Japanese vehicle manufacturers have successively set lightweighting targets. Honda has set weight reduction targets for its main models, Mitsubishi has achieved an average weight reduction of 10% across its models, Mazda has achieved a weight reduction of 100 kg for two consecutive five-year periods in its launched models, Nissan has targeted a 15% weight reduction for models launched after 2015, and Toyota has achieved an average weight reduction of 5% to 10% across all its models in 2015. It is expected that since 2010, lightweighting ratios of 1/4, 1/3, and 1/2 will be achieved by 2015, 2020, and 2030, respectively.
China: Synergistic Development of Materials, Design, and Processes
According to the “Roadmap for Energy-Saving and New Energy Vehicle Technology” issued by the China Society of Automotive Engineers, China’s automotive lightweighting aims to achieve a 18% weight reduction from 2015 to 2020. Aluminum, magnesium alloys, and carbon fiber-reinforced composites will be applied appropriately, with optimized design based on material characteristics and performance requirements. The main process will be cold forming, supplemented by hot forming, roll forming, and laser welding.
By 2025, a 30% weight reduction is targeted, with an expansion in the application of aluminum, magnesium alloys, and carbon fiber-reinforced composites in vehicle bodies. An integrated lightweighting multi-objective collaborative optimization design incorporating structure, materials, and performance will be adopted. The main processes will be hot forming, warm forming, and internal high-pressure forming, supplemented by extrusion forming, bending forming, and thermosetting fiber material forming.
By 2030, fiber composite materials will be the primary focus, supplemented by light alloys and high-strength steel. Integrated design will be conducted considering manufacturing processes and cost control requirements. Thermoplastic fiber material forming, extrusion forming, and bending forming will be the main processes, supplemented by warm forming and hot forming. Driven by policies and the urgent need for lightweighting, the aluminum alloy die-casting market is expected to expand, and aluminum alloy die-casting enterprises with strong material preparation, design capabilities, and advanced processes have great development potential.
