Metal 3d printing using high brightness blue laser systems

Abstract

Many industrially important reflective metals absorb blue light significantly better than they absorb longer wavelengths. That fundamental physical advantage has led to increasing adoption of high-quality, high-speed blue laser welding in emobility, energy storage, and consumer electronics applications, and it was anticipated that the blue laser would bring comparable advantages to additive manufacturing/3d printing. Here we report results from the first integration of the blue industrial laser into a scanner based powder bed fusion system, the EOS M100 additive manufacturing system. The tests were performed with two very different laser systems: the AO-650 (650Watts – 30 mm-mrad) and AI-200 (200Watts – 5 mm-mrad). Test articles were printed with SS316L powder and pure copper powders. The blue laser printed the SS316L parts twice as efficiently as the conventional IR laser. Following minimal process optimization, tensile bars were fabricated and tested resulting in a density of <99% and an ultimate tensile strength of 80,000 psi when printed with the blue laser, even in these preliminary tests. Blue industrial laser printing of copper test blocks achieved <97% full density on as-printed parts. The EOS M100 IR laser could not be tested on the copper because it did not have sufficient power to melt the powder. Here we summarize the integration of these lasers into 3d printing, and present initial test results.