Can metal 3D printing have advantages in heat dissipation components such as motor casings?

一, Integrated moulding of complicated structures: going beyond the physical limits of existing methods
1. Improving the topology of internal channels
Making heat dissipation parts the old-fashioned way involves welding or mechanically processing fins, flow channels, and other structures together. This can cause difficulties like high thermal resistance and leaks. Layer by layer fusion technique makes it possible for metal 3D printing to immediately create integrated moulding of complicated internal flow channels. For instance, Conflux Technology in Australia has made a 3D-printed heat exchanger for Formula One racing cars. It has a spiral flow channel design that increases the heat exchange surface area by 300%, lowers the pressure drop by 40%, and gets rid of the risk of welding joint leakage at the same volume. This form of design can create directional flow channels for the hot regions of motor windings in the application of motor casing, which helps to get rid of heat in a precise way.
2. Very thin walls and a framework with microchannels
The minimal wall thickness for metal 3D printing has gone up to more than 0.1mm. When paired with microchannel technology, this can greatly increase how well heat moves out from the object. The nickel-based alloy heat exchanger that French company TEMISTh and Chinese company Yijia 3D worked on together has improved the heat transfer efficiency between supercritical CO₂ and high-concentration salt solution in the seawater desalination process by 25%. This was done by combining 0.15mm thin fins and 0.5mm microchannels. This kind of structure can keep the temperature rise of power devices within 5 °C during the heat dissipation of electric car motor controllers, which more than triples the lifespan of the devices.
3. The lattice structure is light.
The lattice structure that topology optimisation makes can make things a lot lighter while yet being strong. Bolite made a titanium alloy spindle housing for a certain aerospace company that uses a gradient lattice design. This design not only fits the need for 2000N · m torque bearing, but it also makes the housing 25% lighter than a standard design. This type of design can lower the moment of inertia and speed up the motor's dynamic response by more than 15% when used in a motor casing.
二, Material performance and process synergy: addressing the needs of tough working circumstances
1. Customised use of materials with high thermal conductivity
Copper and copper alloys are the best materials for getting rid of heat because they have great thermal conductivity (pure copper has a thermal conductivity of 401W/m · K). However, because copper is so reflective in traditional processing, it only absorbs 5% of the laser light, which makes melting hard. Xihe Additive's green laser metal 3D printing technology has made copper absorb 40% more laser light. They were able to print a copper heat sink that was 0.5mm thick and had a very thin TPMS (triple period minimal curved surface) structure. The density was 99.9% and the surface roughness was Ra ≤ 3.2 μ m. This made the heat sink 20% more efficient at conducting heat than traditional castings.
2. Printing with a gradient of several materials
3D printing can change the composition of materials in a gradient way to meet the performance needs of different parts of the heat sink. For instance, a machine tool spindle made by a given company has a surface made of high carbon chromium bearing steel (HRC60 or above) and a core made of medium carbon steel. The synchronous powder feeding method makes it possible to bind without seams. This not only makes the cutting edge more resistant to wear, but it also makes the core 1.8 times tougher than typical materials, which lowers the danger of breaking.
3. Controlling thermal stress and making post-processing better
The metal 3D printing process heats up and cools down quickly, which can easily cause residual stress that makes the metal bend or shatter. Oqton 3DXFight programme may use multi-physics When used with hot isostatic pressing (HIP) after treatment, interior pores can be removed, giving 3D printed parts a fatigue life of over 90% compared to forged parts.
三, Optimising the cost of the whole life cycle, from making one unit to making a lot of them
1. The cost benefit of customising small batches
3D printing can save money on mould development costs (traditional die-casting moulds cost between 500,000 and 2 million yuan) for small and medium-sized heat dissipation components that make less than 5,000 pieces a year. The cost per piece can also be cut by 30% to 50% compared to traditional methods. For instance, one company utilises the Platinum BLT-S400 to print aluminium alloy motor casings. The cost of the material is just 25% of the selling price, while the waste rate for traditional forging and machining techniques is as high as 60%.
2. Quick changes and checking the design
With 3D printing, "design print test optimisation" can be done in a closed loop, which cuts the development time from 6–12 months in traditional methods to 2–4 weeks. The micro cooler that IQ Evolution Company in Aachen, Germany, made with a PCB can go from concept to sample delivery in just 72 hours using 3D printing. This is 10 times faster than traditional methods. It can also quickly change the flow channel parameters for different power semiconductors, like SiC components.
3. Restructuring the supply chain and distributed manufacturing
With 3D printing, you can "local print, global distribute," which is a way of making things in different places. Siemens Energy's 3D printing service centre in Germany can quickly fix gas turbine blades for European customers, cutting the delivery time from six weeks to 72 hours. Companies can set up 3D printing nodes in the primary market for motor cooling parts to cut down on inventory and shipping expenses. By setting up five 3D printing centres around the world, a domestic motor firm has cut the time it takes to get replacement parts from 45 days to 7 days and cut inventory expenses by 60%.
四, Example of an industry application: from testing the idea to making it in large quantities
1. How to keep electric vehicle batteries cool
The Tesla Model Y has a 3D-printed nickel-based alloy battery cooling plate with biomimetic vein flow channels that keep the battery pack's temperature difference within 2 °C. This makes the car 40% more efficient than traditional harmonica tube cooling solutions. SLM Solutions equipment from Germany prints the cooling plate in one piece in 12 hours, which cuts down on the number of steps needed by 8 compared to traditional stamping and welding methods.
2. How aeronautical motors get rid of heat
The Airbus A350 XWB has a motor housing made of 3D-printed titanium alloy that has heat-dissipating fins and a lightweight lattice structure. It meets EMI shielding standards and cuts the weight from the usual 8.2 kg to 5.3 kg, which helps the plane lose 300 kg of weight each plane. AddUp, a French startup, used electron beam selective melting (EBSM) technology to print the shell. This made it 99.95% dense and 15% stronger against fatigue than forged parts.
3. How the industrial servo motor controller gets rid of heat
The HD7X series servo drive from Huichuan Technology uses a 3D-printed copper alloy heat dissipation base plate and microchannel arrays to keep the temperature of IGBT modules from rising above 65 °C. This increases the power density by three times compared to traditional aluminium extrusion heat dissipation solutions. The Platinum A400 machine prints the bottom plate, which cuts the cost of each component by 45% compared to traditional brazing methods. There is also no risk of solder corrosion.