Pure copper and copper alloys are widely used in the fields of power, heat dissipation, pipes, decoration, etc. due to their excellent electrical conductivity, thermal conductivity, corrosion resistance and toughness. Some copper alloy materials have good electrical conductivity, thermal conductivity and comparative High strength, widely used in the manufacture of aerospace engine combustion chamber components. However, with the increasing demand for complex structural parts on the application side, traditional processing techniques have gradually failed to meet the demand.
Recently, the American company Markforged has launched a method for successfully 3D printing copper parts. This process is expected to be widely used in manufacturing fields such as electric vehicles.
More economical and complex copper parts
Due to the excellent thermal conductivity and reflectivity of copper, this makes copper metal difficult to handle inside the 3D printer. Although current selective laser melting (SLM) 3D printing technology can be used to manufacture copper metal powder materials. However, in the process of laser melting of copper metal, the absorption rate is low, and it is difficult for the laser to continuously melt the copper metal powder, resulting in problems such as low forming efficiency and difficult control of metallurgical quality. In addition, the high ductility of copper makes post-treatment work such as removing excess powder more difficult.
Previously, Fraunhofer ILT launched a green laser solution, which is shorter than the wavelength of 1μm wavelength, at 515nm. This means less laser power output. In addition, the laser beam can be focused more accurately, enabling it to manufacture finer parts using the new SLM process.
However, Markforged`s copper 3D printing process is not the same as the green laser solution introduced by Fraunhofer ILT. It is different from the powder bed selection laser melting metal 3D printing process. Markforged uses extruded 3D printing technology. Challenges to be solved to reduce the cost of automobile production and manufacturing, while improving the efficiency of electric vehicle motors.
In terms of electric vehicles, electric drive and control systems are the core of electric vehicles and the biggest difference from internal combustion engine vehicles. The electric drive and control system consists of drive motor, power supply and motor control device. The other devices of electric vehicles are basically the same as those of internal combustion engines. The electric drive subsystem is composed of an electronic control unit, a controller, an electric motor, a mechanical transmission device, and driving wheels. The main energy subsystem is composed of main energy, energy management system and charging system. The auxiliary control subsystem has functions such as power steering, temperature control and auxiliary power supply.
Motors using cast copper rotors can help ordinary induction motors effectively reduce the rotor losses of the motor, thereby helping to improve the efficiency of the motor. While the motor losses are reduced, the energy converted into thermal energy is reduced, which reduces the temperature of the rotor and stator coils.
The 3D printed copper metal process developed by Markforged will be expected to solve the challenges of casting and brazing of cast copper parts for electric vehicles. It will replace casting and brazing to achieve more economical, more complex and more efficient production of copper parts. The manufacture of radiators, sensors and other parts.
Different from the laser metal melting 3D printing process in selected areas, the 3D printing copper metal process developed by Markforged mixes copper and plastic materials into copper wires, and then constructs the components layer by layer by extrusion melting. This process is just melting plastic, and Not melting copper. Then, the copper is put into the sintering furnace to remove the plastic material.
3D printing provides the ability to economically manufacture smaller, more complex, and high-tolerance parts. Currently, an example of how automakers can improve quality while saving costs is the 3D printing of copper welding handles through the Markforged process. Used for spot welding body parts. Most large automakers may purchase up to $ 1 million in spare toolholders from external suppliers. And if the manufacturer can make a smaller and more compact welding handle, it can be welded in a narrower space, which means that less spot welding can be used, because the welding seam can be closer to the desired position, this pair High-performance cars are very useful.
A manufacturer has performed thousands of test welds with Markforged's 3D printed braze handles, which has reduced the delivery time of parts by 12 times and the cost of parts by 6 times.