This new breakthrough enables virtually all complex underbody parts of electric vehicles to be die-cast into one piece. This will be key to Tesla's future plans to produce affordable electric cars and achieve profitability. It can develop a car from scratch in 18-24 months. 3D printing, industrial sand and custom alloys play important roles.
According to foreign media citing five people familiar with the matter, Tesla has achieved a technological breakthrough in integrated die-casting, which will be the key to Tesla's plan to produce tens of millions of affordable electric vehicles and achieve profitability in the next decade.
With this breakthrough, Tesla can die-cast nearly all of the complex underbody parts of an electric vehicle into a single piece, instead of just about 400 parts.
It is reported that this new technology is the core of Tesla’s “Unboxed Assembly Process” assembly system. When Tesla announced the assembly system in March, it stated that it would be used to support the production of low-priced models. It is expected that It can reduce the production cost of electric vehicles by 50% and reduce factory space by 40%.
Sources pointed out that with this new technology, Tesla can develop a car from scratch in 18-24 months, while most of its competitors may currently take 3-4 years.
Tesla has been planning a $25,000 small electric car. This report points out that this model may use an oversized casting frame to combine the front, parking space, and bottom of the body (where the battery is placed). Tesla is expected to decide whether to do so as soon as this month, and the final product may change during the design verification process.
Terry Woychowski, president of American engineering company Caresoft Global, believes that if Tesla can die-cast most of its chassis components in one piece, it will further subvert the way cars are designed and manufactured. "This is an extremely powerful enabler and has a huge impact on the entire industry. But it is also an extremely challenging task and castings are very difficult to make, especially the larger and more complex castings."
▌3D printing, industrial sand and custom alloys
Tesla's breakthrough this time mainly lies in two aspects: one is how to design and test giant molds for mass production; the other is how the castings combine hollow subframes with internal ribs to reduce weight. weight and improve crashworthiness.
The two innovations were jointly developed by multinational design and casting experts and involved the use of 3D printing, industrial sand and custom alloys.
In fact, for automakers, "integrating larger parts" has always been a problem: making larger molds can indeed improve efficiency, but it is expensive and brings countless risks.
One casting expert said that once a large metal test mold is made, each machining adjustment during the design process can cost $100,000, and completely redoing the mold can cost $1.5 million. Another person said that the entire design process of a large metal mold usually costs about $4 million. As a result, most automakers shy away from it. Because from the aspects of noise and vibration, assembly and surface treatment, ergonomics and crashworthiness, it may take at least six adjustments to design a perfect mold.
Despite the risks and difficulties, sources pointed out that Musk’s original vision was to find a way to die-cast the entire underbody in one piece.
To this end, Tesla turned to companies that use 3D printing and industrial sand to make test molds. Through digital design files, a binder jet machine is used to deposit liquid adhesive onto a thin layer of sand and build it layer by layer. A mold in which molten alloy can be die-cast.
One source said that even with multiple versions, the design verification process of sand casting is extremely cheap, only 3% of the cost of metal prototypes - which means Tesla can adjust the prototype as many times as needed and build it in just a few seconds. Print a new prototype within hours.
The cost advantage is on the one hand, and on the other hand, after using sand casting, the design verification cycle only takes 2-3 months, while the metal mold prototype takes 6-12 months.
In addition, the subframe of a car chassis is usually hollow to reduce weight and improve crashworthiness. To cast the hollow subframe, Tesla plans to place a solid sand core printed by a binder jet machine throughout the mold. Once the part is die-cast, the sand core will be removed, leaving a void.
However, during this process, due to the different performance of the aluminum alloy originally used to produce castings in sand molds and metal molds, it was unable to meet Tesla's crashworthiness and other standards. Therefore, casting experts have overcome this problem by creating custom alloys.
Once Tesla finalizes the prototype mold, it can invest in making the final metal mold for mass production.
▌Tesla’s new models provide excellent use opportunities. Many car companies have followed up on integrated die-casting.
Tesla is currently developing two small cars: one for personal use and another for Robotaxi. Sources pointed out that their underbody structures are relatively simple, which also provides an excellent opportunity for Tesla's new technology to be used.
Of course, if Tesla determines that it will die-cast the underbody of the integrated body, it must decide which die-casting machine to use, and this choice will also determine the complexity of the car frame-in order to quickly die-cast such a large part, Tesla will need a new For larger die-casting machines, the clamping force needs to reach or exceed 16,000 tons, which is more expensive and may require larger factory space.
However, the high clamping force cannot accommodate the 3D printed sand core required to create the hollow subframe. People familiar with the matter said Tesla could solve this problem by using a different type of die-casting machine. This method slowly injects the molten alloy while containing the sand core and tends to produce a higher quality casting; however, the process takes more time.
Tesla has always been a solid supporter and practitioner of integrated die-casting. According to information released by the company, with the use of integrated die-casting technology, the 80 stamped and welded parts of the original Model Y plan can be integrated into one casting, achieving a 40% cost reduction and a 10% weight reduction.
It is worth noting that most of those who followed Tesla to join the integrated die-casting team were new energy car companies such as Weilai, Xpeng, and Ideal, while traditional car companies were very few. Now, in addition to Toyota, General Motors, Hyundai Motor, Volvo Cars, etc. have also begun to plan to adopt this technology.
When it comes to the overall industrial chain, Guotai Junan believes that the upstream consists of heat-treatment-free aluminum alloy materials, die-casting machines and die-casting moulds. The gross profit margin of integrated die-casting molds is 40%, the net profit rate is 20%, the single-link profit is the highest, the technical barriers are the highest, and the pattern is decentralized. ; The midstream includes third-party die-casting plants and vehicle manufacturers with self-built production lines. Competition in this segment is fierce. A few aluminum casting suppliers with core advantages occupy the supporting market for most mid-to-high-end models; the downstream directly connects with OEMs.
Minsheng Securities also pointed out that integrated die-casting products are expected to expand from rear floor products to front cabin, mid-floor, battery tray and other related parts. It is recommended to pay attention to Ikodi, Xusheng Group, Wanfeng Aowei, Ruihu Mold, Merrill Lynch, Rongtai Technology, Bojun Technology, Duoli Technology, Xiangxin Technology, Huada Technology, Wencan Technology, Guangdong Hongtu, Lizhong Group, Lijin Technology, Yizumi, Xingyuan Zhuomai, and Heli Technology.
