TY - JOUR
T1 - Reducing near-surface voids in metal (Ti-6Al-4V) powder bed fusion additive manufacturing
T2 - the effect of inter-hatch travel time
AU - Diehl, Brett
AU - Nassar, Abdalla
N1 - Funding Information:
This effort was performed through the National Center for Defense Manufacturing and Machining under the America Makes Program entitled “Generation and Characterization of Parameter- and Process-induced Defects” and is based on research sponsored by Air Force Research Laboratory under agreement number FA8650-16-2-5700 . The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/12
Y1 - 2020/12
N2 - Powder bed fusion additive manufacturing (L-PBF) is being rapidly adopted by industry for the production of novel and complex geometries. However, production of L-PBF parts with near-surface voids remains a primary concern. Such voids impede the use of additive manufacturing for thin geometries and may significantly reduce fatigue life. Here, we develop a statistical model which relates the probability of near-surface void formation to toolpath parameters used in part production. Using registered computed tomography (CT) data as ground truth to measure void location and morphology together with actual build plan data (e.g. vector trajectories, powers, speeds), we identify the time between nonconsecutive, adjacent hatch strikes to be a statistically significant (p = 8.54 × 10-20) indicator of the likelihood that a given point becomes a void. Furthermore, we show that altering hatching strategy to include fewer short hatches (i.e. a longer time between nonconsecutive, adjacent hatch strikes) can produce a similar geometry with significantly fewer near-surface voids.
AB - Powder bed fusion additive manufacturing (L-PBF) is being rapidly adopted by industry for the production of novel and complex geometries. However, production of L-PBF parts with near-surface voids remains a primary concern. Such voids impede the use of additive manufacturing for thin geometries and may significantly reduce fatigue life. Here, we develop a statistical model which relates the probability of near-surface void formation to toolpath parameters used in part production. Using registered computed tomography (CT) data as ground truth to measure void location and morphology together with actual build plan data (e.g. vector trajectories, powers, speeds), we identify the time between nonconsecutive, adjacent hatch strikes to be a statistically significant (p = 8.54 × 10-20) indicator of the likelihood that a given point becomes a void. Furthermore, we show that altering hatching strategy to include fewer short hatches (i.e. a longer time between nonconsecutive, adjacent hatch strikes) can produce a similar geometry with significantly fewer near-surface voids.
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U2 - 10.1016/j.addma.2020.101592
DO - 10.1016/j.addma.2020.101592
M3 - Article
AN - SCOPUS:85091245625
VL - 36
JO - Additive Manufacturing
JF - Additive Manufacturing
SN - 2214-8604
M1 - 101592
ER -