Large-dimension metal parts produced through laser powder bed fusion

Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing technology in which a defined metal powder thickness is selectively melted with a laser, according to the geometry of the part being produced. The layer-by-layer approach allows manufacturing functional complex shaped components, with high structural integrity at low cost. This technique has been proven to produce near net-shape parts up to 99 % relative density and has viable economic benefits. However, the typical build envelope for this type of machines is of 300x350x250 mm, thus the manufacturing of large-dimension parts is unachievable. The goal of this project was to develop a customized LPBF machine with a build envelope of 1020 mm x 1020 mm x 520 mm that is able to produce high quality parts. Through fine-tuning of the processing parameters, the machine has produced samples with 316L stainless steel which exhibit relative densities above 99 %. Besides the samples, the machine has also successfully built large-dimension parts. The results obtained are a positive indicator towards the ultimate goal of zero-defect manufacturing.