Recently, Guangdong Hongtu, a china aluminum alloy auto parts manufacturer, announced that Xiaopeng Motors finally chose the company as the supplier of integrated structural parts for a certain model of the chassis it is developing. Previously, Guangdong Hongtu has introduced a set of 6800T die casting island and completed the trial mode, and signed a contract to purchase a set of 12000T die-casting island in early 2022.
In addition to Guangdong Hongtu, in the first few months of this year, some other companies reported projects related to ultra-large integrated aluminum die casting: for example, Wencan Group’s world’s first 9000T die-casting island was successfully trial-produced at its Tianjin production base, and continued to build from Idra, a subsidiary of LK Group, purchased 9 sets of X-PRESS series large-scale two-plate die-casting machines, and will take the lead in establishing large-scale and super-large die-casting island production lines in China; Xiaomi Auto also signed a contract with a domestic mainstream die-casting machine manufacturer , purchase more than one set of super-large tonnage die-casting machines from the latter for integrated die-casting auto parts manufacturing projects and so on. According to incomplete statistics from Antaike, more than 20 domestic auto and parts manufacturers have invested or are about to invest in integrated die-casting projects. Fengaowei, Top Group and other well-known enterprises.
The working principle of integrated die casting is to heat and melt the metal into a liquid state, squeeze and pour it into the mold with power, and wait for the metal to cool and solidify to obtain parts that conform to the shape of the mold. Compared with the traditional and mature die-casting process, the products produced by this technology are very large in size, and can combine dozens of parts into one super-large part. Tesla is a pioneer in advocating integrated die-casting technology. As a science madman, Musk’s pioneering work is to expand the application scope of integrated die-casting from the previous smaller automotive aluminum die-casting parts to super-large automotive structural parts, and also achieve large-scale mass production.
Of course, the emergence of this technology has put forward higher requirements for the tonnage of die-casting equipment, and also requires better comprehensive performance for the die-casting aluminum alloy used. The existing die-casting aluminum alloy obviously cannot meet the strict requirements of large-scale integrated die-casting process and product performance. Require. In fact, as early as two years ago, Tesla was reported to have developed a new type of aluminum alloy product, which has high yield strength, high electrical conductivity and excellent casting properties, which can be used to produce parts for electric vehicles through the die-casting process. Tesla has also patented the alloy specifically. At that time, the outside world thought that Tesla wanted to use this alloy to produce motor rotors, stators, busbars, inverters and other aluminum parts for electric vehicles. Component performance does not meet requirements. But in fact, Tesla’s move is to develop and apply integrated die-casting technology in advance. Two years later, Tesla’s application of this technology is accelerating. This large-scale integrated die-casting machine, which weighs several hundred tons and covers an area the size of a basketball court, has been put into use in four Tesla factories around the world. The Cybertruck model is also expected to follow after its Model Y applies integrated die castings. Major foreign automakers such as Volkswagen, Volvo and Mercedes-Benz, as well as a number of new domestic automakers, have also followed suit, investing in integrated die-casting projects. The promotion and application of this technology in the automotive field seems to be the general trend. Domestically, with the rise of integrated die-casting, alloy research and development has also followed up rapidly. The heat-free integrated forming aluminum alloy developed by Lizhong Group Longda Aluminum has obtained a national invention patent.
According to estimates by some institutions, the global penetration rate of integrated die casting is expected to reach 30% in 2030. It is conservatively estimated that the value of bicycle accessories is expected to reach 10,000 yuan, with a market value of more than 240 billion yuan. Obviously, part of the capital market is also optimistic about the application prospects of the integrated die-casting market, and firmly believes that new revolutionary technologies and investment opportunities have arrived.
Compared with the traditional production process, the advantages of integrated die casting are:
• Significant Reduction In Production Time
The one-piece die-casting, known as a mega or giga, that Tesla uses in its Model Y is a one-piece part that replaces steel stampings and small aluminum parts that used to have to be welded by large robots. Compared with the traditional manufacturing process, the vacuum high pressure die casting (HPDC) process adopted uses aluminum alloys that can obtain suitable performance without heat treatment, and uses the integrated china die casting technology to directly make the rear body floor, rear wheel arches, and rear cross rails. A single cast aluminum part is used, and the large parts that require more than 70 parts to be assembled in the traditional process are reduced to only a few integrated die-casting parts, and the manufacturing time is shortened from 1-2 hours to a few minutes. Save the unit production cycle.
• Improved Stability And Aesthetics Of Body Structure
Compared with components made of dozens of components and through welding, riveting and other connection technologies, the structural stability of large components produced by integrated die casting is better. At the same time, the appearance aesthetics has also been improved, and the welding marks that were visible to the naked eye almost disappeared. Even Musk himself said in a stomping manner that the fundamental reason why the Model 3’s seams are so obvious is that the latest integrated die-casting technology is not used like the Model Y.
• Save The Floor Space Of The Production Line
Although the integrated die-casting machine is huge in size, because it replaces a considerable number of large robots and other equipment, and the products do not need heat treatment, the overall length of the production line is shortened, saving 30% of the equipment footprint.
• Manufacturing Materials Are Easier To Recycle
After the production process is replaced by stamping-welding and integrated die-casting, the whole process becomes relatively simple, and it is easier to recycle the waste generated during the production process. At the same time, different grades of aluminum alloys including die-casting, deformed alloys, and stamping steels are all replaced by single-grade die casting aluminum alloys, and it is easy to achieve closed-loop recycling of manufacturing materials.
• Reduce The Number Of Workers
Due to the reduction of the number of equipment and the simplification of the process, the previous number of production line workers is no longer required, which further improves the production efficiency.
But everything has two sides, and this is also true of large-scale integrated die casting, a production process developed primarily for the automotive industry. At least from the current initial stage, there are still some shortcomings in this technology, which will take time to solve or improve in the future, including the following aspects.
• The Cost Reduction Advantage Is Not Obvious
For OEMs, several factors need to be comprehensively considered in the design and production process of automobiles. In the fierce market competition, how to reduce costs on the premise of meeting the requirements of multiple parties is undoubtedly one of the factors that needs to be prioritized. Tesla’s bold adoption of this technology should be mainly for the purpose of reducing costs and increasing efficiency. It can be seen from the previous analysis that the goal of improving production efficiency has been initially achieved, but whether to reduce costs remains to be considered. Although Tesla claims that the integrated die-casting technology has saved Model Y’s manufacturing costs by 20%, this does not mean that other companies using this technology can achieve the same effect. There are several difficulties in reducing costs. hinder.
First of all, for the production equipment, the integrated die casting machine seems to reduce the number of large robots and the length of the production line, which makes the equipment investment of a single die-casting machine have certain advantages. Equipment, trimming machine, conveyor belt, oil temperature machine, high vacuum equipment and other peripheral equipment are also considered to form the die-casting island required for actual production, and the entire operation and maintenance cost is actually not low. The calculation results of some securities companies also show that the overall investment of large-scale integrated die-casting islands is higher than that of equipment using traditional stamping + welding processes.
Secondly, there are also difficulties in reducing costs at the technical level. Compared with the previous die casting, the integrated die-casting process saves the important link of heat treatment. The key to solving the problem lies in the use of a heat-free die casting aluminum specially developed for this technology. Tesla solved the problem of heat-free heat treatment through Charles Coyman, a talented man in the field of materials dug from Apple with a high salary, but not all car companies can acquire such talents, and they may not necessarily have the ability to develop such materials. At the same time, the cost of molds using this technology is also high. Foreign research results show that the service life of large-scale integrated castings at this stage is much lower than that of stamping parts. Typically, the service life of a die casting mold depends in part on the alloy. Structural aluminum alloys that have not been heat treated can reduce mold life compared to 380 cast aluminum alloys that are widely used in gearboxes and motor housings. In order to die-cast such large-scale automotive aluminum parts, the mold design process is also more complicated, which further increases the cost of mold use.
• Less Than Ideal Weight Loss
Globally, whether it is a traditional fuel vehicle or a new energy vehicle, the issue of lightweight must be considered. However, in the process of promoting the use of integrated die-casting technology, Tesla has rarely mentioned the weight reduction effect it can play. Typically, aluminum die castings are well suited for stiffness-driven designs, but the downside is that their wall thicknesses can only go down to 2-3 mm at best, compared to 0.7 mm for automotive sheet. Existing data shows that Tesla’s overall die-casting parts are 20% heavier (8 kg) than the replaced sheet metal parts, which did not achieve better weight reduction.
• Not In Line With The Prevailing Trend Of Multi-Material Mixing
After a long period of practice and aluminum profiles, the main engine factory has basically abandoned the design idea of using a single material, and mixed use of high-strength steel, aluminum, magnesium, carbon fiber reinforced composite materials and other materials. According to different performance requirements, various materials are used. Each performs its own duties and gives play to their own characteristics, which ultimately reflects the advantages of mixed use, which has become the mainstream development trend in the future. However, integrated die-casting does the opposite, unifying multiple materials into one material, and there may be cases where the performance of some locations is lower than the original requirements.
• Promotional Use Has Limitations
From the perspective of industrial layout, OEMs need to consider many factors when choosing large-scale integral die casting parts or thin-plate parts. Large-scale integrated die-casting parts are more likely to be used by companies in new factories, rather than by auto companies that have invested in sheet metal manufacturing. . In addition, due to high initial equipment and production investment costs, integrated castings are unlikely to be widely used in low-volume vehicle manufacturing, but are suitable for models with an annual output of at least 100,000 vehicles. For Tesla, this is obviously not a problem, but for other companies, especially for new car-making forces such as Weilai, Xiaopeng, and Ideal in China, there are not many single models that can sell more than 100,000 vehicles per year. . Therefore, when other car companies follow up this technology, they must combine the expected sales scale of their own products.
• Substantial Increase In Later Vehicle Maintenance Costs
In the later use of models with high aluminization rate, a disadvantageous factor is the high maintenance cost. Since aluminum alloy parts cannot be repaired by sheet metal, once they are damaged, they need to be replaced as a whole. The emergence of integrated die-casting components further magnifies this situation. Once a problem occurs, the replacement of large integrated components will greatly increase the maintenance cost of the vehicle.
Through the above comprehensive analysis of the integrated die-casting technology and products, it can be seen that its product features and existing advantages and disadvantages are obvious. Musk continues to carry forward the traditional aluminum die casting technology in the field of automotive applications, and his innovative spirit is beyond doubt. The emergence of this technology has also brought new vigor and vitality to aluminum die casting products in the automotive application field, opening up new growth space, and may also change the previous judgment on the development trend of automotive aluminum. In the context of the development trend of vehicle lightweighting and electrification, in the process of converting fuel vehicles to electric vehicles, people are more optimistic about the increase in the unit consumption of deformed aluminum alloys in the field of passenger cars, and more optimistic about aluminum body panels, body-in-white aluminum panels and The future of aluminium extrusion products. If the integrated die casting technology enters the development stage from the initial stage in the application of new energy vehicles in the future, the use of deformed aluminum alloys, especially the increase in the proportion of aluminum extrusion materials, is obviously unfavorable. For Tesla, in addition to the rear bottom plate of the frame, it also plans to use an integrated casting process to produce parts such as the front bottom plate and battery shell of the car. According to Musk’s plan, if these can be realized, more than 370 original parts will be replaced, and aluminum extrusions will be directly replaced on battery trays, battery shells or some body structural parts. Whether integrated die casting can catch up in the field of automotive aluminum involves many factors, and traditional deformed aluminum alloy aluminum cnc machining enterprises need to carefully study and deal with them. For new energy vehicles, which are not bound by traditional design concepts and can be freely innovated, the suitable material has not yet been finalized. Whether it is integrated die-casting, aluminum rolling, or aluminum extrusion technology, I have mastered the technology. The law of development can only go further and have the last laugh.