According to the market observation of 3D Science Valley, from a worldwide perspective, the cutting-edge research that promotes 3D printing for new electric drives is forming a number of development trends: one trend is That Ford and RWTH Aachen to develop flexible and sustainable 3D printed motor parts, the focus of which is copper metal; the other trend is Fraunhofer IFAM or exone through more economical printing methods to achieve new motor parts, the focus of which is screen printing or binder Jetting adhesive jet 3D printing; one trend is the UK's manufacturing technology centre MTC fully 3D printed motors, which focus on product redesign; the last trend is the Connactive project or Porsche and GKN's project, which focuses on the combination of new materials and new designs.
▲The technical logic of the 3D printing copper motor windings
3D Science Valley "Copper Metal 3D Printing White Paper Second Edition"
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Copper has a hole in the sky
Pure copper and copper alloys due to excellent conductivity, thermal conductivity, corrosion resistance and toughness and other characteristics, is widely used in electricity, heat dissipation, pipelines, decoration and other fields, some copper alloy materials because of good conductivity, thermal conductivity and high strength, is widely used in the manufacture of aviation, aerospace engine combustion chamber components. However, with the increase in the demand for complex structural parts at the application end, the traditional processing technology has gradually been unable to meet the demand. 3D printing technology has the advantages of forming complex structural parts, high material utilization, no need for molds, etc., and this technology has great application potential in the preparation of pure copper or copper alloy radiators and heat exchangers, tail nozzles, motor windings and other parts with complex functions integrated.
3D Science Valley
The rapid development of /3D printing motors
According to the market observation of 3D Science Valley, from a worldwide perspective, the cutting-edge research that promotes 3D printing for new electric drives is forming a number of development trends: one trend is That Ford and RWTH Aachen to develop flexible and sustainable 3D printed motor parts, the focus of which is copper metal; the other trend is Fraunhofer IFAM or exone through more economical printing methods to achieve new motor parts, the focus of which is screen printing or binder Jetting binder jet 3D printing; one trend is the fully 3D printed motor dedicated to by MTC, the UK's manufacturing technology centre, which focuses on product redesign; the final trend is the Connective project or porsche and GKN project, which focuses on the combination of new materials and new designs.
According to the market observation of 3D Science Valley, the development of electric vehicle motor stator windings is often a well-known bottleneck, and 3D printing can avoid this development obstacle with almost no mold. Since traditional production involves complex bending and welding processes, the time savings brought about by 3D printing pay off especially on so-called hairpin windings. In this issue, 3D Science Valley works with Gu You to perceive how 3D printing can achieve the key components of electric vehicle electric drive through the latest development of copper in the motor stator winding of 3D printed electric vehicles.
The maximum output power of a motor is limited due to its preheating, for example due to the permissible winding temperature. There are usually two levers to increase power limits: first, to reduce losses with the same power, and second, to improve heat dissipation. The design of the windings plays a major role here, as it is the main source of heat.
Classic circular windings have many limitations: copper conductors, winding processes and notch geometries must match. The conductors that are wound around each other form a solid pattern. In addition, circular wires (the classic conductor shape) do not fit well with trapezoidal grooves in geometry. As a result, each groove is half filled with copper, creating a void. The relatively small conductor cross-section ensures large electrical losses.
Making copper have a higher filling rate, 3D printing has unique advantages in this regard. In this regard, the well-known L-PBF selection laser metal melting 3D printing technology and the Binder Jetting adhesive jet metal 3D printing technology are currently the most important application technologies.
▲exone
Among them, in terms of adhesive jet metal 3D printing technology, ExOne cooperated with the innovative motor company Maxxwell to develop and produce motor copper coil windings, changing the design thinking of motor coils for more than 100 years. Traditional process of copper wire or copper sheet, in the narrow motor stator, rotor space is difficult to show the optimal design, 3D printing will bring certain changes.
▲ 3D Science Valley "Copper Metal 3D Printing White Paper Second Edition"
l Commercialization of 3D printed additive manufacturing motor stator windings
According to the market observation of 3D Science Valley, in the market, the German company Additive Drives manufactures motor stator windings by 3D printing additively, and is expected to significantly improve part performance.
German Additive Drives has achieved higher degrees of freedom through 3D printing, and through the SLM selection metal 3D printing process based on powder bed, the copper content in the groove is greater. Physically, this means a maximum cross-section of the turn and a smaller resistance. The variable shape achieved by 3D printing is also conducive to heat dissipation, because each wire is in thermal contact with the so-called laminated iron core of the coil, so there are no hot spots.
With the development of lasers, the application of 3D printing copper has moved towards a benign development trend, according to the market observation of 3D Science Valley, in the 3D printing of stator windings, due to the saving of winding tools, through 3D printing can be economically produced up to 500 units below the small batch motor stator windings. Lower harness resistance, fewer losses, shorter winding heads, all add value to the motor.
According to the market understanding of 3D Science Valley, the current limit that 3D printed motor stator windings can currently withstand is about 1 MW, but for commercial prospects, it is more appropriate to focus on the power range of about 100 kW, as this is common in automotive traction motors.
l Industrialized 3D printing additive manufacturing motor stator windings
Together with thyssenkrupp Systems Engineering and the DAP Institute of RWTH Aachen University, Ford is developing flexible and sustainable production of electric motor components on one production line. The name of the project is HaPiPro2, which refers to hairpin technology. Hairpin windings are a new technology in the field of electric motors, and rectangular copper rods replace winding copper wires. The process is easier to automate than conventional winding motors and is particularly popular in the automotive sector because it can significantly reduce manufacturing time.
Suitable for rapid prototyping, 3D printing is able to feed measurement results back into simulation in real time, ensuring the required operational performance and improving quality assurance. The HaPiPro2 project is investigating how to further develop the method in order to efficiently produce different models of electric motors on a single production line.
▲ ACAM Additive Manufacturing Center Aachen
The HaPiPro2 project aims not only to efficiently build efficient electric motors, but also to develop various flexibilities in production. RWTH Aachen University, a member of the ACAM R&D consortium, brings expertise related to application-oriented research to the entire hairpin production process chain. The tasks of RWTH Aachen University also include analyzing causality and testing digital methods in production plans.
Ford promised in February 2021 that by 2024, all European commercial vehicle series will be available in all-electric versions or versions with plug-in hybrid drives. Ford expects to achieve two-thirds of commercial vehicle sales in all-electric models or plug-in hybrids by 2030. By mid-2026, all European Ford passenger cars will be available in electric versions, and by 2030 they will be fully converted to pure electric vehicles.
According to 3D Science Valley, Ford Europe's first all-electric fuel-volume vehicle will be manufactured in Cologne from 2023, and the company has invested $1 billion in the new Ford Cologne Electrification Center, creating the conditions for the transition to a purely electric future.
High-speed, high-frequency and power-density eDrive solutions
Based on what 3D Science Valley understands, the Connactive project was founded in 2019 and is dedicated to enabling high-speed, high-frequency, and power-density eDrive solutions. This cross-company collaboration will take advantage of the different areas of expertise of each member, and the results will drive the development of modern electric engines.
Currently, the metal powder from H gan s is used in Connactive's first project: a dual drive system, a powered split star gear set and a matching RX II unit, combined with a high-torque AX motor and highly integrated electronics. Through the collaborative capabilities of partner companies Dontyne Gears, Moteg and Vishay, the dual-drive system went from blueprint to standard prototype for series production within six months.
Currently, according to the understanding of 3D Science Valley, the solvative results of the project are expected to take electric drives to the next level and accelerate the introduction of the market at the lowest total cost.
/Copper material
In terms of copper materials, according to the market observation of 3D Science Valley, in addition to pure copper, and CuNi2SiCr copper alloy powder materials, the typical 3D printed copper alloy powder materials that have been put into use include the high-strength, high-conductivity copper-based alloy GRCop-42 developed by NASA (National Aeronautics and Space Administration), the CuCrZr and CuNi3Si materials developed by GKN, and the CuSn10 and CuSn8 developed by Heraeus.
In China's additive manufacturing enterprises, Youyan Powder New Materials Co., Ltd. carried out the research and application of copper and copper alloy powder for additive manufacturing earlier in China, and has formed a full range of additive manufacturing special copper and copper alloy powder products, including pure Cu, CuSn10, CuCrZr, CuNi2SiCr, CuAlFeNi, etc.
Xi'an Polarite has made progress in the field of copper metal laser forming, developed a 3D printing process for refractory metals and high thermal conductivity, high reflection metals, realized the copper material manufacturing process of complex runners, and successfully prepared 3D printing copper alloy tail nozzles; Changsha New Materials Industry Research Institute Co., Ltd. and other material enterprises have carried out the research and development of CuCrZr copper alloy 3D printing powder.
German company Deyi Technology (Taicang) Co., Ltd. provides copper powder with low laser reflectance, which is suitable for L-PBF laser powder bed metal 3D printing process.