Increased Productivity of Ferrous Alloys Produced by Powder Bed Fusion - Laser Beam
Licentiate thesis, 2024
The initial study found that achieving consistent processability of low alloy steels across layer thicknesses, as indicated by the as-printed density, is better correlated with surface energy density (SED) J/mm2 rather than volumetric energy density (VED) J/mm3. Regions with high densities above 99.8% exhibited similar ranges of SED at different layer thicknesses, explained by the resulting melt pool depths being more similar than at similar ranges of VED.
The second study addressed the impact of three- and four-factor increase in hatch distance and layer thickness compared with state of the art. It was observed that the influence of VED on density was poorly described as differences of up to 7.5% in density were measured at the same VED. More accurate representations of impact on main print parameters on density was found by regression analysis which also captured the interaction between laser power, scan speed and hatch distance at different layer thicknesses. Build rate increase can be realized by numerous combinations of basic laser parameters, however this results in distinctive porosity characteristics and even at the same levels of build rate increase, pore characteristics, such as orientation, aspect ratio and size, can differ significantly.
additive manufacturing
process optimization
build rate
build speed
powder bed fusion – laser beam
porosity
low alloy steel
316L stainless steel
productivity in AM
Author
Rasmus Gunnerek
Chalmers, Industrial and Materials Science, Materials and manufacture
Impact of high-productivity process parameters in powder bed fusion–laser beam on microstructure of stainless steel 316L
European Journal of Materials,;Vol. 3(2023)
Journal article
Gunnerek, R; Hearn, W; Hryha, E "Improving productivity of low-alloy steels produced by powder bed fusion - laser beam"
Subject Categories
Manufacturing, Surface and Joining Technology
Other Materials Engineering
Metallurgy and Metallic Materials
Areas of Advance
Materials Science
Publisher
Chalmers
Virtual Development Laboratory (VDL)
Opponent: Dr, Henrik Karlsson, Volvo Technology AB, Sweden