Laser Powder-Bed-Fusion: From the fundamentals (materials characterisation and evaluation of mechanical properties) to certification (design, manufacture and inspection) and beyond.

Laser Powder-Bed-Fusion (L-PBF) is an additive manufacturing (AM) process by which a layer of powder is deposited onto a substrate and spread uniformly by a wiper and then a high power-density fibre laser fully melts the pre-deposited powder layer according to a specific computer-generated two dimensional pattern. The melted particles fuse and solidify to form a layer of the component. The part retracts vertically and powder is deposited on top. The process is repeated until the three dimensional part is completed.

The key to achieving full density, and consequent enhanced mechanical performance, in components produced via L-PBF is to fully understand the sources of the defects and to control these rigorously and methodically. In order to explore some of the fundamentals to addressing the sources of these defects this presentation aims to:

• Investigate the effect of key processing parameters and their effect in regions of limited thermal conductivity in the L-PBF build envelope.
• Explore the role of dendrite growth and cooling rates in the densification mechanism of part produced by L-PBF.
• Report on the effects of L-PBF beam characteristics.
• Examine the influence of powder on the development of porosity within L-PBF builds and the consequent effect on fatigue performance.
• Highlight the key challenges and essential steps required for the certification of parts manufactured by L-PBF.