Can metal 3D printing achieve lightweighting of parts in the casting industry?

1. A big step forward in technology: going from "subtractive manufacturing" to "additive thinking"
The design freedom of traditional casting processes is limited by factors like parting surfaces and draft angles. This is why parts structures often have a "solid" aspect. For instance, the cylinder block of a car engine needs to have thicker walls to make it stronger, but this also makes it heavier. Metal 3D printing technology can make items with complicated internal structures by melting metal powders layer by layer. This is called "on-demand shaping."
Design for topology optimisation: Metal 3D printing can make lightweight structures like honeycomb and lattice designs by using simulation software to show how the parts will move. For instance, a company has made a high-entropy alloy for 3D printing that is 200% more resistant to oxidation than standard nickel-based alloys at a high temperature of 600 °C. Topology optimisation has made aeroplane engine turbine blades 30% lighter and 15% stronger at the same time.
Biomimetic structural applications: Lightweight design is based on natural structures like bones and honeycombs. A certain research team created a bionic knee joint module that uses a 0.12mm titanium alloy mesh structure. The DeepSeek algorithm optimises the stress distribution in real time, which doubles the lifespan compared to traditional CNC machined parts and cuts the weight by 60%.
Integration of internal channels: Metal 3D printing makes it possible to directly make complicated structures like lubrication channels and conformal cooling channels. A particular car firm is employing 3D printed sand moulds to make prototypes of commercial card water-cooled motor housings. The internal spiral flow channel design has increased the effectiveness of heat dissipation by 40%. The weight has dropped from 12 kg to 8 kg, which is a 33% decrease.
2. When to use it: From expensive tools to the things that people need to survive
Metal 3D printing's small weight has spread to many industries, and its uses are growing from high-end fields like aerospace and automotive manufacture to consumer electronics, medical gadgets, and other aspects of daily life.
Aerospace: Every kilogramme less weight on an aeroplane can save tens of thousands of yuan in fuel expenditures each year. By putting in 3D printed seat belt buckles with honeycomb slots, a specific company has made a single plane 5 kg lighter and saved more than 10,000 yuan a year on fuel costs. In addition, lightweight design has made the aircraft 8% to 12% lighter by using 3D printing to make titanium alloy engine mounts, aluminium alloy cabin door hinges, and other parts.
Vehicles that use new energy: The driving range is directly affected by making basic parts like battery packs and motor casings lighter. A specific new energy vehicle firm has started using 3D-printed sand moulds to make prototypes of commercial card water-cooled motor housings. This cuts the manufacturing time from 60 days to 10 days and the prices by more than 80%. At the same time, optimising the internal flow channel has lowered the motor's temperature by 15 °C and increased the driving range by 5%.
Devices for health care: Personalised implants need to find a balance between being biocompatible and light. A medical company employs 3D printing to make titanium alloy hip joints. The lattice structure design lowers the weight from the usual 200g to 120g and keeps the porosity between 60% and 80%. This helps bone cells grow and cuts the patient's recuperation time after surgery by 30%.
3. Normal Case: A Useful Path from the Lab to the Factory
Swapping out forging for casting in automotive chassis brackets
Forging technology is widely used to make traditional car chassis brackets, however they only employ around 40% of the material and need to be processed many times. A company used 3D printing technology and topology optimisation design to make the QT800-5 bracket out of ductile iron. This made it 40% lighter, going from 15 kg to 9 kg, while still being strong. Bench road tests have shown that this bracket works. When it was used to replace standard forged steel parts, the weight of a single vehicle went down by 27.4 kg and the cost of the materials went down by 174.8 yuan.
Shape synergy of the blades on an aircraft engine
Engine blades for aeroplanes have to be able to handle high temperatures, high pressures, and high-frequency vibrations. It's hard to regulate grain refinement and performance uniformity with typical casting methods. One company employs SLM technology to make blades out of nickel-based alloys. By directing the direction of grain formation using the directional energy deposition technique, the strength against fatigue goes up by 25%. The service life is also three times longer than that of typical blades, and the operating temperature is lowered by 50 degrees Celsius through the construction of internal cooling channels.
The "miniaturisation breakthrough" for humanoid robot joints
Humanoid robots need joints that are very light and very precise. A company showed off the world's first metal 3D printed optical based six axes force sensor, which includes a fingertip sensor that is only 8.5mm wide and 7mm thick. By combining the internal lattice structure with the circuit, it makes sure that signals are sent reliably and cuts the weight down to a third of what typical systems do. It has been used successfully to sense the force on robot fingertips.