What is 3D Printing?
Selective Laser Melting (SLM), 3D printing, is a type of Additive Manufacturing, which involves building pieces layer by layer. The data from the CAD 3D design is converted into a 2D layer profile. The object is built as each layer of fine metal alloy powder, approx 30-60microns thick, is then selectively melted by laser to form the solid object. The wiper pushes the excess powder off the plate, which drops to then apply another layer of powder. The process starts with a solid metal plate and the part is built from it. The part is attached to the plate using a support structure which is removed after the build is complete. Due to the metal powder being melted there are very high local temperatures which cause deformation and warping however with good design and part orientation these can be minimized. SLM is different from “sintering” as the parts SLM produce are fully dense and have mechanical properties similar to that of wrought bar from a metal supplier.
This 3D printing process enables rapid prototyping of complex, high tech objects, with intricate interior detail. Powder Materials that are able to be used in the production process are Titanium 64, High-Strength Stainless Steel 15-5-PH, Stainless Steel 316 and Inconel 718, a High-Temp Alloy.
Why use this technology?
SLM manufacturing process has provided the opportunity for complete design freedom, with much quicker R&D. Tooling for prototyping is no longer required, thus ensuring very low development costs, in much quicker timeframes. Added to this, highly complex structures with intricate internal details, not previously able to be manufactured by traditional methods are now easily printed.
Customisation is cost-effective and quick, with intricate changes easily changed in the CAD 2D model, no tooling rework required. Production is design driven, and is aimed at all industries from Aerospace, Automotive, Medical, Military and Industrial Products as the material we predominately us, Titanium 64, is one of the most versatile, corrosive resistant and cost effective super alloys to manufacture.
Can any part be selective Laser melted?
In theory…Yes. But in a practical sense…Not always. Similar to conventional machining, whereby you would generally make a shaft in a lathe and a bracket in a mill, a parts success in SLM depends a lot on the shape. Where a part has intricate details which are difficult to machine, or areas of curves and complex surfaces, these parts lends itself well to SLM manufacturing. Additionally, if a piece/part can be redesigned to achieve its function with a minimal amount of material, then with a little design focused towards SLM, the part can be created more efficiently and often cheaper than conventionally manufactured. To gain the best results from SLM, a designer must forgo the conventional thought process of removing material from a block and start thinking of material addition only where it is needed from a blank canvas.
What equipment is used?
With SLM being a newtechnology, there are limited machines available for commercial use worldwide. Here at RAM, we now have four Selective Laser Melting machines printing around the clock, which enables us to offer different materials to be printed, with prompt delivery times. Machine specifications can be provided with capacity sizes. Two Renishaw AM250 SLM machine was commissioned mid 2015 to meet the growing demand for SLM production pieces. This machine runs primarily in Inconel 718, with the build size 245mm x 245mm x 280mm and enables a third alloy powder to be offered."
Two Reinshaw Additive Manufacturing machines were commissioned mid-2015 to meet the growing demand for SLM production pieces. This machine runs primarily in Inconel 718, with the build size 245mm x 245mm x 280mm.
This machine is producing intricate parts for prototyping and manufacturing in Titanium Alloy. The chamber build size is 280mm x 280mm x 350mm.