Can metal 3D printing create complex fluid channel structures?

1. Technical principle: accurate conversion from digital models to tangible structures.
The layering properties of additive manufacturing are what make metal 3D printing useful for making fluid channels. For example, the process flow for selective laser melting (SLM) technology can be broken down into three steps:
Digital modeling: Use CAD software to make a three-dimensional model of a fluid channel that optimizes the flow path, cross-sectional shape, and surface roughness factors. For instance, Sino Power's multi-proportional valve block for undersea special equipment uses AI algorithms to automatically create a flow route topological structure, which cuts fluid resistance by 40%.
Layered slicing: To make a laser scanning route, cut the model into thin layers that are 20 to 50 μm thick along the Z-axis. Platinum Technology's intelligent process library can automatically match the laser power, scanning speed, and other settings for different materials. This keeps the accuracy of the channel wall thickness under ± 0.05mm.
Melting layer by layer: A high-energy laser beam selectively melts metal powder along a route while being protected by inert gas. This creates a solid by stacking layers on top of one other. Electron beam melting (EBM) technology uses electron beam scanning in a vacuum environment. It is good for making materials that are hard to process, such high-temperature alloys that are used to make cooling channels for aircraft engine turbine blades.
This "from scratch" manufacturing method does away with the need for molds and cutting tools in traditional processes. It can also directly create any complex flow channel, including geometric shapes that are hard to make with traditional methods, like spiral flow channels, multi-stage branch flow channels, and biomimetic tree-like flow channels.
2, Situation for use: Breakthrough practice in the realm of high-end manufacturing
Aerospace: A common use case is the cooling channel of the turbine blades in an aviation engine. To put up cooling tubes using traditional casting methods, you have to drill or weld them together. This might cause leaks and make the cooling less effective. And you may use metal 3D printing to make an internal labyrinth flow channel that lets cooling gas evenly cover the blade surface. This greatly improves the engine's thrust-to-weight ratio. The LEAP engine fuel nozzle made by GE using 3D printing technology combines 20 flow channels into one, which makes it 25% lighter and 15% more fuel efficient.
Biomedical: The design of the fluid channel in tailored implants has a direct effect on how well tissue can heal. For instance, 3D-printed hip implants have porous channels with biomimetic bone trabecular features that help bone cells proliferate. Clinical feedback demonstrates that the time it takes for bones to integrate is cut in half. Maxwell Medical, a smart manufacturing company in Xi'an, produced a 3D-printed intervertebral fusion device with an internal flow channel that can mimic the fluid circulation of natural intervertebral discs. This cuts the risk of problems after surgery by 30%.
Energy and Power: 3D-printed flow channel heat exchangers improve the efficiency of heat transmission by 20% and cut material use by 40% by improving the geometry of the flow channel in the cooling system of nuclear reactors. Xi'an Ouzhong Technology produced a titanium alloy flow channel plate for solar equipment that evenly distributes cooling liquid using micrometer-level flow channel design. This keeps the temperature of the single crystal furnace within ± 0.5 ℃.
3, Technological edge: a double breakthrough in design freedom and better performance
Design Freedom Revolution: Traditional procedures are limited by the angles at which molds may be demolded and the tools that are available. The design of the runner must also take into account how easy it is to manufacture. 3D printing can make flow channels at any angle or curve. For instance, Sino Power's valve block for undersea equipment uses 3D printing to combine the original 12 process holes into 3 continuous flow channels. This cuts the volume by 60% and the pressure loss by 25%.
Optimizing the performance of materials: Metal 3D printing can create fine grain structures and make materials stronger since it solidifies quickly. The flow channel parts made of TC4 titanium alloy by Platinum Lite have a tensile strength of 1100MPa, which is 15% stronger than forgings. Topology optimization design also makes the product 30% lighter, which meets the aviation industry's need for "lightweight+high-strength."
Cost and time savings in manufacturing: Making a traditional hydraulic valve body takes 12 steps, such as casting, machining, and welding, and can take up to 6 months. 3D printing can turn raw materials into completed goods all in one place. Sino Power's hydraulic valve block project has cut the delivery time down to two weeks and lowered mold costs by 90%. 3D printing is more cost-effective for small batch custom products.
4. Technical problems and ways to get around them
Metal 3D printing has a lot of potential for making fluid channels, but it still has three big problems to solve:
Control of surface roughness: The surface roughness of the flow channel made by the SLM process is normally Ra250-400 μ m. To achieve sealing criteria, this needs to be brought down to Ra10 μ m or lower using electrolytic polishing or shot peening. Xi'an Jiaotong University created ultrasonic vibration-assisted SLM technology that can make the flow channel's surface roughness Ra50 μ m, which cuts down on the number of steps needed after processing.
Finding defects inside the flow channel: It's hard to see defects like absence of fusion and porosity. Platinum equipment has developed industrial CT scanning equipment that can find interior flaws as small as 0.1mm. The flaw detection rate has gone up to 99.9% when used with an AI image recognition method.
Multi-material composite printing: To make complex fluid systems work, you often need to combine diverse materials, like channels that don't corrode and structures that are very strong. Xi'an Ouzhong Technology's laser arc composite printing technology has made it possible for titanium alloy flow channels and stainless steel structures to be connected in a way that is not uniform. This technology has a tensile strength of 400 MPa, which is what marine engineering needs.