The automobile industry undergoes a manufacturing revolution approximately every forty years, and Tesla is leading the current new revolution. From Ford's assembly line production to Toyota's lean production to Volkswagen's platform-based modular production, the leader of each automobile production revolution will have a clear advantage in subsequent market competition. With two important technological innovations, 4680CTC, and integrated die-casting, Tesla is leading a new round of manufacturing revolution in the automotive industry.
- 4680CTC: The battery pack is integrated into the vehicle body and directly connected to the seat. The high level of integration reduces the weight of the vehicle by 10%, increases the cruising range by 14%, reduces the number of parts by 370, reduces the unit cost by 7%, and reduces the unit investment by 8%. Currently, 4680CTC has been mass-produced in the Austin, Texas, factory.
- Integrated die-casting: After the Model Y integrated die-cast rear floor reduced the number of parts from 70 to 1 to 2, the application of the technology continued to expand. The current solution at the Austin, Texas, plant can reduce the number of front and rear floor parts from 171 to 2, and reduce the number of welding points by more than 1,600.
New forces & traditional OEMs follow up on integrated die-casting:
New forces:
- NIO joins hands with Wencan Co., Ltd. to adopt an integrated die-cast rear subframe for the ET5;
- Xpeng Motors joins hands with Guangdong Hongtu to roll out the integrated structural parts of the 6800T chassis;
- Gaohe Automobile joins hands with Tuopu Group to roll out the integrated super-large die-cast body rear cabin, reducing weight by 15~20%.
Traditional OEM:
- Mercedes-Benz launches the latest scientific research results in the world - VISION EQXX. The rigidity of the rear part of the body is greatly improved, and it is expected to reduce weight by 15-20%;
- Volvo will invest 10 billion Swedish kronor in its Swedish factory to introduce new technologies and manufacturing processes, including integrated die-casting.
Skateboard chassis has become an important driving force for the medium and long-term development of CTC and integrated die-casting. The skateboard chassis is one of the most important revolutionary technologies in the current automotive industry. The technologies involved include a non-load-bearing body, wire-controlled chassis, integrated electric drive system, and highly integrated intelligent modules. In addition, improving the mass/volume energy density of power batteries in a limited space is highly consistent with the CTC battery system integration solution; after high integration, the structure of the chassis becomes more complex, and integrated die-casting can better meet the needs of chassis technology improvement.
The heavy weight of new energy vehicles and the increase in the cruising range has forced the development of lightweight vehicles. Compared with fuel vehicles of the same class, the weight of pure electric models is approximately +19~32%, and that of plug-in hybrid models is approximately +12~18%. In order to improve energy efficiency and extend cruising range, the lightweight development of new energy vehicles has become inevitable.
Aluminum alloy is the most cost-effective, and high-pressure die casting is more efficient. Replacing steel with aluminum can reduce the weight of the body-in-white by about 1/3, but aluminum metal has a high thermal conductivity, which can easily cause problems such as reduced weld performance and contamination of electrodes by the oxide layer on the alloy surface; high thermal expansion coefficient can easily lead to large deformation of parts. High-pressure die-casting has high efficiency and small wall thickness of processed parts. It is an efficient processing technology suitable for aluminum alloys. Integrated die-casting is based on high-pressure die-casting. The parts produced do not require additional internal connections and the process is greatly reduced. In addition, the material utilization rate of die-casting scrap is as high as 90%, which is much higher than the 60%-70% of stamping & welding steel bodies.
The application of integrated die casting in automobiles can be further expanded. We believe that by adjusting the strength and stretch rate, the die-casting process will be applied to more structural parts and covering parts. More parts other than the body, such as motors and battery pack casings, can be manufactured using the die-casting process in the future.
The technical barriers to integrated die castings are mainly reflected in four aspects:
- Large die-casting machine: The system is complex and has high requirements for theory, experience, and manufacturing technology; the "design-test-design" cycle is long and the time cost is high; the cost is high and the risk cost is high.
- Material formula: The alloy melt needs to have good rheological properties, small linear shrinkage, and a small solidification temperature range. The key is to avoid heat treatment.
- Die-casting mold: Die-casting has higher requirements in terms of temperature, vacuum, molding scheme, process parameters, post-processing, etc., and the mold is more complex.
- Process method: High-speed mold filling characteristics can easily lead to casting failure, which requires high requirements on all process elements.
Integrated die-casting can significantly improve production efficiency and reduce manufacturing costs. Take the following car body assembly as an example. Compared with traditional stamping & welding processes, integrated die-casting can significantly reduce the amount of stamping and welding used. The processing steps are reduced from 9 to 2; supporting labor is also reduced accordingly. With an annual production capacity of 450,000 vehicles Calculated in a factory, the number of workers will be reduced from 120 to 30; the number of parts will be reduced from >370 to 2~3, the number of link points will be reduced, and the cost will be reduced; working hours will be reduced from 2 hours to 180s, and 5 die-casting machines will be It can meet the annual production capacity of 600,000 pieces.
The market size of integrated die-casting bodies is expected to exceed 20 billion yuan in 2025. Calculated based on a car body rear floor production line with an annual production capacity of 500,000 pieces, the costs of the traditional stamping and welding process and the integrated die-casting process are 630 million yuan and 480 million yuan respectively. The integrated die-cast rear floor bicycle can save costs by 300 yuan. We estimate that the integrated die-casting body market size is expected to reach 21.5 billion yuan in 2025, with a CAGR of 132% from 2021 to 2025.
Tesla leads a new round of manufacturing revolution: 4680 CTC + integrated die-casting
In the century-old automobile industry history, a manufacturing revolution occurs every forty years or so. From Ford's assembly line production in the 1910s, to Toyota's "multi-variety, small batch" lean production in the 1950s, to Volkswagen's platform-based and modular production in the 1980s, the leaders of each automobile production revolution will be in the future. Occupy a clear advantage in market competition.
Tesla manufacturing revolution: 4680CTC+ integrated die-casting. Tesla’s 4680CTC solution (CTV) integrates the battery pack into the car body and directly connects it to the seats, significantly reducing the number of parts and improving assembly production efficiency. The integrated die-cast front and rear floors of the Model Y body subvert the traditional stamping and welding process. Compared with the traditional stamping and welding process, there are 169 fewer parts and the cost is significantly reduced. According to information released by Tesla on Battery Day, relying on two revolutionary technologies, the vehicle can reduce weight by 10%, increase cruising range by 14%, and reduce the number of parts by 370.
4680 CTC: Tesla battery technology has always been the benchmark for industry innovation
Tesla leads the trend of power battery innovation. When the Model S / Currently, Model Y equipped with the CTC solution of 4680 cells has been delivered. In the past ten years, Tesla has continued to lead the development of the industry in both battery cells and packs.
4680 CTC: Be the first to announce specific plans and lead the industry’s technical direction
Tesla disclosed a patent called INTEGRATED ENERGY STORAGE SYSTEM in June 2021, which details the 4680 Structural Battery (CTC) battery system integration technology. According to the publicly disclosed content in the patent, we can have an overall directional understanding of Tesla CTC: the battery pack upper cover is directly connected to the vehicle structure such as the seat, becoming the structure of the passenger cabin floor; the cells are filled with resin Materials, Tesla believes that this can provide thermal protection on the one hand, and structural support for the battery core on the other hand; in comparison with the "large module" solution, the CTC solution has the advantages of reducing support parts, reducing the weight of the vehicle, Increase overall battery capacity.
4680 CTC: Model Y officially launched, Texas factory starts delivery in Q1
Tesla’s CTC solution can increase vehicle cruising range by 14%, reduce unit costs by 7%, and reduce unit investment by 8%.
In Tesla's 2021 Q4 financial report, it can be seen that workers in the Texas Gigafactory directly connected the Model Y seats to the 4680 CTC battery pack. The implementation of CTC will significantly improve its final assembly production efficiency.
Integrated die-casting: starting with Y, continuing to promote the advancement of lightweight car bodies
Integrated die-casting: dedicated layout and continuous breakthroughs in research and development
Tesla has deployed a 6,000-ton large-scale die-casting machine-GigaPress in all four of its major automobile factories. Currently, the Shanghai factory has equipped five large die-casting machines for the production of Model Y rear floors. The Texas factory just started mass production in March. On the basis of the rear floor of Model Y, it has added integrated die-casting of the front floor (front longitudinal beam).
Layout-integrated die-cast aluminum alloy patent, titled "Die-cast aluminum alloy for structural components," describes an aluminum alloy that is both strong and has excellent ductility that requires no further processing and can significantly reduce production costs. .
The Tesla energy absorption system will be integrated with the support system. On July 5, 2021, Tesla applied for a patent for "integrated energy-absorbing castings". This energy-absorbing system is widely used in automobile collision structures. The energy-absorbing system can be integrated with part or all of the support structure through a single casting process, thereby reducing the need for processes including spot welding, seam welding, riveting, bolting, gluing, etc.
Integrated die-casting: components are expanded to the front floor, and the overall number of solder joints is reduced by 1,600+
Tesla's integrated die-casting extends to the front floor. According to Tesla's announcement, in 2020 Tesla announced the Model Y integrated die-casting rear floor plan, which can reduce the number of parts from 70 to 1~2; the 2022 Q1 financial report announced the integrated die-casting produced at the Austin, Texas, factory The body plan can reduce the number of front and rear floor parts from 171 to 2, and reduce the number of welding points by more than 1,600.
Integrated die-casting: Mass production at Texas factory to accelerate technology application
The die-casting machine Giga Press used by Tesla is produced by Lijin Technology, and its floor space can be saved by 35% compared to production equipment using traditional stamping and welding processes. According to Tesla’s financial report information, the Shanghai Gigafactory has five large-scale die-casting equipment for production, and the integrated die-casting of the Model Y body front floor (front longitudinal beam) at the Austin Gigafactory in Texas will also be mass-produced.
New car-making forces take the lead in following up on integrated die-casting
NIO and Wencan collaborated on the ET5 integrated die-cast body rear floor. NIO ET5 uses an integrated die-cast rear floor. The integrated casting process reduces the weight of the rear floor of the body by 30%, while increasing the trunk space by 11L. In November 2021, Wencan's 6000T ultra-large die-casting island successfully tested the mold, and the integrated die-cast automobile rear floor product was successfully rolled off the production line.
Xpeng Motors joins hands with Guangdong Hongtu to develop integrated die-casting. 1. At present, Guangdong Hongtu has entered the supporting system of Xpeng Motors, and both parties are simultaneously developing integrated die-casting parts. In January 2022, Guangdong Hongtu 6800T chassis integrated structural parts officially rolled off the production line. 2. The Wuhan base will build an integrated die-casting workshop. The project will be officially launched in July 2021, covering an area of about 1,500 acres, with a planned production capacity of 100,000 vehicles. More than one set of ultra-large die-casting islands and automated production lines will be introduced.
In February 2022, the integrated super large die-cast body rear compartment of Gaohe Automobile and Tuopu was rolled out. The ultra-large structural parts produced by the 7200T die-casting machine are nearly 1700mm in length and 1500mm in width respectively, achieving a weight reduction of 15~20% and shortening the entire development cycle by 1/3. In terms of materials, partner TechCast's high-strength, tough, heat-free aluminum alloy material can avoid problems such as dimensional deformation and surface defects of parts caused by heat treatment. Its fluidity is more than 15% higher than that of materials of the same level, and its plasticity is more than 30% higher, ensuring that The vehicle collision and other performance have reached a higher dimension.
International traditional OEMs follow up on integrated die-casting
Mercedes-Benz releases integrated die-casting results, significantly improving performance. Mercedes-Benz has launched its latest scientific research achievement - VISION EQXX - in the world. The biggest innovation is the application of bionic engineering structural components to the rear of the body and the top of the front tower. The entire rear of the body is formed from an independent and complete aluminum alloy casting. Compared with traditional processes, the rigidity of the rear part of the body is greatly improved, and it is expected to reduce weight by 15-20%.
Volvo will introduce integrated die-casting. Volvo will invest 10 billion Swedish kronor in its Swedish factory, where it will introduce some new and more sustainable technologies and manufacturing processes, including an integrated die-casting process.
Skateboard chassis has become an important driving force for the medium and long-term development of CTC and integrated die-casting
The skateboard chassis is one of the most important revolutionary technologies in the current automotive industry. Its biggest feature is the decoupling of the upper and lower bodies, thereby significantly shortening the vehicle development cycle. Therefore, the skateboard needs to be equipped with a non-load-bearing body structure and a wire-controlled chassis; in order to facilitate loading, the chassis cannot occupy too much vertical space, and integrated electric drive systems such as "three-in-one" have become necessary; highly integrated intelligent modules need to be centralized It is based on EEA and realizes the decoupling of software and hardware; it improves the mass/volume energy density of power batteries in a limited space, which is highly consistent with the CTC battery system integration solution; after high integration, the structure of the chassis is more complex, and integrated die-casting can be more It better meets the needs of chassis technology improvement.
In recent years, many domestic and foreign manufacturers have successively launched self-developed skateboard chassis, and the technology is gradually becoming mature.
Improved battery life of new energy vehicles forces the development of lightweight vehicle bodies
Sales of new energy passenger vehicles continue to grow at a high rate, and are expected to exceed 5.4 million units in 2022. From 2018 to 2021, the sales volume of new energy passenger vehicles were: 1.05, 1.06, 1.20, and 3.32 million units respectively; the penetration rate of new energy passenger vehicles in 2021 is 15.5%. In March 2022, the penetration rate of new energy passenger vehicles reached 24.7%, reaching a new high. We believe that sales of new energy passenger vehicles will exceed 5.4 million units in 2022.
The weight of the three electric systems of new energy vehicles increases significantly. Compared with fuel vehicles, new energy vehicles have fewer engines and transmission systems, but because the battery energy density (about 0.1-0.3KWH/KG) is lower than that of fuel (above 12KWH/KG), the weight of the three-electric system increases significantly. We selected different power versions of several models under several brands to compare and calculate the curb weight. Compared with the fuel version, the weight of the pure electric version increased by about 19% to 32%, and the weight of the plug-in hybrid version increased by about 12% to 18%.
The demand for improved cruising range has forced the development of lightweight vehicles. Compared with traditional fuel vehicles, new energy vehicles are heavier, which seriously affects their cruising range.
Automobile lightweighting can significantly improve the performance of new energy vehicles, mainly in terms of environmental protection, utility, power, safety, and braking.
Aluminum alloy is currently the most cost-effective lightweight material for car bodies
The lightweighting of automobiles is mainly achieved through the use of lightweight materials. The main ways to reduce vehicle weight include structural optimization design, lightweight material application, and lightweight processing and manufacturing technology. Among them, the current main automotive lightweighting measures are mainly the use of lightweight materials.
Among various lightweight materials, aluminum alloy has the highest cost performance. Compared with various metal alloys and composite materials, aluminum alloy has obvious comprehensive advantages in performance, density and price, and is the most cost-effective lightweight material.
Connection technology, structural component performance and size restrict the application of aluminum alloy materials in automobiles
The manufacturing process of aluminum alloy body is far more complex than that of steel body. If aluminum alloy is used instead of steel, the weight of the body-in-white can usually be reduced by about 1/3. Take the Audi A8 as an example. Due to its all-aluminum body, the body-in-white weight is only 215kg. However, the high thermal conductivity of aluminum metal can easily cause problems such as reduced weld performance and contamination of electrodes by the oxide layer on the alloy surface. Moreover, the high thermal expansion coefficient of aluminum can easily lead to large deformation of parts. Still taking the Audi A8 as an example, its body manufacturing requires 14 types of connection processes including MIG welding, remote laser welding, etc. The process complexity is much higher than that of the steel body-in-white, which is mainly resistance welding.
Car body structural parts have high performance requirements and the permeability of aluminum alloy materials is limited. Usually, body structural parts are large in size, complex in structure, and the wall thickness is usually only 2-3mm. They need to have high elongation and high strength to meet safety performance (crash test) requirements and part connection requirements. With breakthroughs in key technologies such as processes/materials/equipment, the penetration rate of aluminum alloy body structural parts is expected to continue to increase.
Die-casting technology continues to progress and innovate
The die-casting process originated in 1885 and was first used in the automobile industry in 1904 in the form of die-cast connecting rod bearings. Die-casting machines have experienced technological breakthroughs such as pneumatic die-casting, cold chamber die-casting, and dual-punch die-casting. Currently, die-casting equipment has developed into a die-casting island with the die-casting machine/mold as the core and assisted by other peripheral equipment.
High-pressure die casting is an efficient processing technology suitable for aluminum alloy materials
High-pressure die casting is an efficient processing technology suitable for aluminum alloy materials. Pressure casting is mainly divided into high-pressure casting, low-pressure casting, differential pressure casting, etc. Among them, low-pressure casting and differential pressure casting are mostly used in the engine and chassis areas, while high-pressure casting is increasingly used in automobile bodies due to its high efficiency and small wall thickness of processed parts, and is an important direction in the future.
Die casting is divided into cold chamber die casting and hot chamber die casting: cold chamber die casting is mainly used in the manufacturing of large parts, such as automotive parts, communication base station cooling components, etc.; hot chamber die casting is widely used in the production of small electronics or 3C products, such as USB connector, laptop case, etc.