Development and Trends of 3D Printing in New Energy Vehicle Manufacturing
The ecosystem of new energy vehicles is open, changing and dynamic. Traditional cars typically take three years from design finalization to new vehicle shipment, during which time the processes and supply chain for the production of these parts go into a solid state. A car company like Tesla, on the other hand, has software that is updated almost every month. The gene of digitalization can be said to be rooted in the blood of the new car-making forces.
The digitization brought about by 3D printing has enabled humanity to generate, for the first time, a real threshold of net economic gain: a demand-driven shift from overproduction to demand-driven production by synchronizing customer behavior with producer behavior.
3D printing is a technology with distinct digital characteristics, which means that additive manufacturing can change the way products are produced intrinsically, not only for personalization, but also for functional-oriented manufacturing, which makes 3D printing a "natural fit" with new energy vehicles in terms of manufacturing genetics.
According to the ACAM Aachen Additive Manufacturing Center, the ACAM Aachen Additive Manufacturing Center's (ACAM Aachen) vision for additive manufacturing in terms of multifunctional materials is an infinite combination of materials and technologies, with the ultimate goal of click-and-produce. Level 1 is a predictable additive manufacturing process; Level 2 is an automated additive manufacturing process; Level 3 is fully automated additive manufacturing (including pre-processing and post-processing); and Level 4 is an integrated and fully automated combination of different manufacturing processes . Currently, the development of additive manufacturing worldwide is mostly at the Level 0 level.
Automotive production requires a high degree of automation, high efficiency, low cost, and consistent quality, which seems to have a lot of "gaps" with the current level of development of 3D printing. Therefore, the current status and future trends of 3D printing in automotive manufacturing need to be understood in the context of the characteristics of 3D printing technology.
According to ACAM Aachen Additive Manufacturing Center, on the one hand, 3D printing has changed the manufacturing logic. Usually for the same product, the more quantities produced by traditional manufacturing technology, the more the cost per part of the product tends to decrease; while for additive manufacturing, the correlation between cost per part and production volume is independent, which is a factor to be considered when considering scalability. On the other hand, regarding the complexity of the product. Usually, when producing parts through traditional manufacturing techniques, the more complex the product, the higher the cost, and the more expensive the company needs to invest (including new tooling and even new equipment to achieve it); whereas for additive manufacturing, the correlation between part complexity and cost is also independent, and the complexity of the part geometry usually does not bring additional manufacturing costs.
For automobiles, while there is a trend toward smaller batches for automotive production, the current integration of 3D printing technology with automobiles is not a factor in this area where the correlation between cost and yield of 3D printing technology is independent, but rather where 3D printing technology achieves more complex products.
In the field of metal 3D printing to reduce the cost of parts, the indirect metal 3D printing technology represented by binder injection metal 3D printing technology, with high speed and low cost has gained a high degree of industry attention. The HP metal 3D printing technology adopted by the public is exactly the binder injection metal 3D printing technology.
The binder injection metal 3D printing technology, from the perspective of production efficiency and economy, fully meets the requirements of automotive-oriented mass production applications. And the rich variety of printable materials (from metal to ceramic, metal-to-metal composites, ceramic-to-metal composites, etc.) further extends the applicable scenarios of binder injection metal 3D printing technology.
In addition to aluminum alloys and copper alloys used in automobiles, steel materials suitable for binder metal 3D printing technology currently include 17-4PH stainless steel, 304L stainless steel, 316L stainless steel, M2 tool steel, H13 tool steel, and also 4140 stainless steel, 420 stainless steel, 4340 stainless steel, 4605 stainless steel, and other materials under development .
In addition, the rapid development of plastic 3D printing and carbon fiber composite 3D printing has enriched the technological options for automotive 3D printing.
The automotive industry needs to take advantage of the specific advantages of 3D printing technology to enhance product design, however, one of the major challenges to break through in order to use 3D printing for specific automotive parts production is the economics. Currently, most of the automotive parts used for 3D printing are small batches of a dozen or so, and to increase to the up to one million production volumes commonly required by the automotive industry, 3D printing will have to break through the economics barrier.
The following will explore the current status and development trend of 3D printing technology in the field of new energy vehicles by introducing the latest application progress of 3D printing technology in Volkswagen, Ford, BMW and other companies.
VW released plans in 2019 to use HP metal 3D printing technology in VW vehicles, starting with mass customization and manufacturing of decorative parts, and integrating HP's HP Metal Jet metal 3D printed structural parts into next-generation vehicles as soon as possible, with an eye on increasing part sizes and technical requirements.
VW aims to manufacture 50,000 to 100,000 football-sized parts per year, which may include things like gearshifts and mirror mounts. Additive manufacturing is being deployed in the growing electric vehicle production sector for its lightweighting benefits. Currently, VW has established the California Innovation and Engineering Center (IECC), introduced a unique concept car with integrated 3D printing, and soon announced the production of 10,000 metal parts on the HP Metal Jet with GKN and HP. It is this milestone that paves the way for VW's continued collaboration with HP and the integration of VW's 3D printed structural parts into its next generation of vehicles.
Metal binder jet 3D printing technology will drive 3D printing technology in VW manufacturing toward maturity, making the technology cost effective. To take advantage of binder jetting, VW is expanding its partnership with HP to lay out additional capacity and bringing in Siemens to provide specialized software for the technology.
With Siemens' automation and software solutions, VW will be able to develop and produce parts faster, with more flexibility and using fewer resources. So far, the first automotive parts manufactured using binder jetting have been sent to VW's Osnabrück plant for certification. The part is used in the A-pillar of the VW T-Roc convertible and, according to the data, is half the weight of a conventional part made from steel sheet.
Ford announced in 2021 that it plans to adopt 3D printing technology in the manufacture of vehicles at scale. Ford has had some degree of success with 3D printing technology before, though at the time it only involved lower volumes. But Ford's technology now extends well beyond low-volume 3D printing production applications, with 3D printed parts being developed for full production of Ford's "very popular models.
Ford's powder for binder jet metal 3D printing is Al6061, and the implications of successfully applying aluminum to 3D printed production of automotive parts are significant: the shift from traditional manufacturing processes to 3D printing processes will reduce weight, save space, and improve part performance by simplifying design, as well as saving cost and time.
For 3D printing next-generation electric motors, Ford has also formed an alliance with ThyssenKrupp and RWTH Aachen University to begin a study to develop a flexible and sustainable production process for next-generation electric vehicles. The name of the project being developed is HaPiPro2, referring to hairpin technology. Hairpin winding is a new technology in the field of electric motors, where rectangular copper rods replace wound copper wires. The process is easier to automate than conventional wound electric motors and is particularly popular in the automotive sector because it can significantly reduce manufacturing time.
The development of motor stator windings for electric vehicles is often a well-known bottleneck. The classical round wire winding has many limitations: the copper conductors, the winding process and the slot geometry must match; the conductors wound around each other form a solid pattern; in addition, the round conductors (the classical conductor shape) do not fit geometrically well with the trapezoidal recesses, with the result that each recess is half filled with copper, thus creating voids. The relatively small conductor cross-section ensures larger electrical heat losses.
3D printing avoids this development hurdle by eliminating the need for almost any tooling. Since conventional production involves complex bending and soldering processes, the time savings from 3D printing pay off, especially in the so-called hairpin windings.
Allowing a higher fill rate of copper, 3D printing offers unique advantages in this regard. Currently, the market is familiar with L-PBF selective laser metal melting 3D printing, as well as binder jet metal 3D printing, both of which are the most dominant application technologies.
By 3D printing motor copper coil windings, we are changing the way we have thought about motor coil design for over 100 years. The traditional process of copper wire or copper sheet is difficult to show the optimal design in the small space of motor stator and rotor, and 3D printing will bring certain changes.
BMW held a joint project kick-off meeting for IDAM in Munich in March 2019 to pave the way for additive manufacturing to enter automotive series production. The IDAM team is pushing additive manufacturing technology in the direction of specific requirements to produce parts of consistent quality as well as individual spare parts based on specific components. The goal is to manufacture at least 50,000 series-produced parts and more than 10,000 spare parts per year using 3D printing technology. the IDAM line contains an open architecture that can be adapted to any LPBF system (selective laser metal melting 3D printing technology).
In 2020, BMW invested 15 million euros (over 100 million RMB) in the official launch of the Munich 3D printing plant, which establishes the BMW Group as a leader in additive manufacturing technology for the automotive industry.
Supported by the German IDAM program, BMW's 3D printing plant in Munich has also built a modular and almost fully automated 3D printing production line. The line covers the entire process from digital design to 3D printing and manufacturing of parts to post-processing. Thanks to the modular structure of the line, which can be upgraded if necessary, the individual modules can be adapted to different production requirements and also allow flexible control of the process steps. By taking into account the requirements for integration into the automotive production line, the project partners have reduced the manual part of the process chain from about 35% at present to less than 5%. At the same time, the unit cost of 3D printed metal parts was cut in half.
The above cases illustrate that many new designs, although not yet industrialized and still in their initial stages, will be overtaken by other companies and will soon find themselves at a competitive disadvantage if manufacturing companies do not make early preparations and innovate in spare parts and prototypes, starting with innovative thinking about design.