A narrative has sprung up that Additive is – or could become – an automated method of manufacturing high quality parts directly from CAD with significant cost and time savings. For this narrative to have any useful meaning places an emphasis on understanding; ‘how’ automated, ‘how’ good, ‘how’ expensive and ‘how’ quickly can Additive make parts?
For Additive to be useful it must be a stable repeatable process with a stable supply chain behind it. For those working in the Additive field there also needs to be a good understanding of the requirements of the part to be made and the conventional supply chain alternatives when the manufacturing method is selected.
Selective Laser Melting is only about 10 years old
Laser powder-bed Additive manufacturing has come a long way in the 10 years since the arrival of the industrial fibre laser brought stable high beam quality at a wavelength well absorbed by metals.
Previously powder metals had been laser sintered to produce materials of varying quality – and ‘density’ was a key concern. The development of fibre lasers, along with improvements in scanning software and purge gas flow have radically changed the core process and current generations of powder bed machines provide a highly repeatable Selective Laser Melting process, though the term ‘sintering’ still persists and causes some confusion.
The full melting achieved in current generation equipment creates dense materials with properties defined by their chemistry and microstructure – not inherent defects. This stable platform of laser + software + Additive equipment hardware has allowed the development of processes, materials and supply chain for laser powder bed Additive manufacturing. There is now a widespread acceptance that laser/Additive is a credible manufacturing method for low volume industrial products in high grade materials.
