In my previous article, part 1 of this series, I raised the point of how Additive Manufacturing (AM) can help speed up the conventional manufacturing process of tools through the conformal cooling of those tools. The utilisation of AM technology for the manufacture of certain tools contributes significantly in bringing down the cost of the tool and the time to manufacture it. It can also improve productivity of the tool as well as ensuring that the final product is less likely to be rejected during quality checking procedures.
Here, in the second article in this series, I am going to consider another major advantage of AM — the ability to reduce the weight of the component significantly without compromising on the functional parameters. This is a key area that is being explored at Wipro, and we have been doing a great deal of research around it. Take for instance this exhaust nozzle (see Image 1). The wall of the discharge nozzle is usually designed to be robust and sturdy to ensure durability since it is the first exit point of searing gas or fluid. The fluid needs to flow through a considerable pathway before it is cool enough to be released into the surrounding atmosphere safely. Simple day to day examples would be the exhaust pipe of a vehicle or an exhaust pipe of an industrial chimney.
In house research and experimentation at Wipro looked at how this exhaust nozzle could be redesigned to bring in efficient and almost instant cooling without compromising on the functional parameters of the part. It is imperative that I mention here that there is a significant amount of domain knowledge that is required before one attempts to re-design an industrial component. Even more so if the component is used in a highly sensitive area that could potentially put someone in a harms way. This has been a subject covered on 3DPI in the past, notably by Graham Tromans, and it cannot be over stated how important this is.
Image 1 shows the original, solid component that has been manufactured using conventional means. The nozzle has an 8 mm wall. It has a small inlet valve and a larger outlet nozzle to reduce the pressure. The nozzle would then direct the gas to flow through several feet of conduits, thereby allowing it to cool, before being released in to the open atmosphere.
Image 2 shows a re-designed nozzle, specifically for AM. The 8mm wall remains to ensure there is no change in the design that would hamper the fitment of this component in situ. But the ‘magic’ is that the 8mm wall is a combination of 2mm solid + 4mm lattice + 2mm solid. That is, there is a 4mm layer of lattice structure that is sandwiched between two solid walls. (For this article, the surface of the component has been sliced open in a diamond shape to show the lattice structure that is beneath the 2mm wall as shown in the image).
The benefits of this proved to be immense in terms of our research. The weight of the component decreased by 45% without compromising on any of its original industrial grade strength. Furthermore, the inbuilt lattice structure brought down the temperature of the exhaust gas resulting in a far lesser amount of conduit pipes being required. As stated, these were just in-house experiments. But the same can be applied to jigs and fixtures that undergo enormous temperature changes during manufacture. Many a time these fixtures rupture because of frequent swing in temperatures. This can be brought down if the fixture has a built in cooling system – like this sandwiched lattice structure.
These initial experiments do suggest that a thorough look at re-designing industrial components can bring about a significant revolution in redesign of the entire tooling and machining industry itself. As mentioned before AM may not be the most suitable technology for mass manufacturing across the board – but it can surely help conventional manufacturing do things in a more efficient manner.