TY - GEN
T1 - The Effect of Oxygen and Carbon on Molybdenum in Laser Powder Bed Fusion
AU - Braun, J.
AU - Kaserer, L.
AU - Letofsky-Papst, I.
AU - Leitz, K. H.
AU - Kestler, H.
AU - Leichtfried, G.
N1 - Publisher Copyright:
© European Powder Metallurgy Association (EPMA)
PY - 2020
Y1 - 2020
N2 - This paper presents molybdenum manufactured by Laser Powder Bed Fusion (LPBF) and the detrimental and positive effects of oxygen and carbon as its impurity and alloying element, respectively. The effects of manufacturing temperature, solidification mechanism, and grain boundary strength, are discussed. It was found that oxygen is responsible for the cracks in LPBF of molybdenum regardless of the processing temperature. Alloying molybdenum with 0.45 wt.% carbon diminishes the detrimental effects of oxygen by three effects: Firstly outgassing of carbon monoxide, secondly by increasing the grain boundary surface through constitutional undercooling and thirdly by trapping the oxygen within the carbide which has good coherency to the molybdenum matrix. The hardening effects of the finely dispersed carbide network must be overcome by building temperatures of 800 °C and higher to prevent cold cracking. The herein presented alloying and processing strategies enable molybdenum to be manufactured in LPBF free of cracks.
AB - This paper presents molybdenum manufactured by Laser Powder Bed Fusion (LPBF) and the detrimental and positive effects of oxygen and carbon as its impurity and alloying element, respectively. The effects of manufacturing temperature, solidification mechanism, and grain boundary strength, are discussed. It was found that oxygen is responsible for the cracks in LPBF of molybdenum regardless of the processing temperature. Alloying molybdenum with 0.45 wt.% carbon diminishes the detrimental effects of oxygen by three effects: Firstly outgassing of carbon monoxide, secondly by increasing the grain boundary surface through constitutional undercooling and thirdly by trapping the oxygen within the carbide which has good coherency to the molybdenum matrix. The hardening effects of the finely dispersed carbide network must be overcome by building temperatures of 800 °C and higher to prevent cold cracking. The herein presented alloying and processing strategies enable molybdenum to be manufactured in LPBF free of cracks.
UR - http://www.scopus.com/inward/record.url?scp=85125069825&partnerID=8YFLogxK
M3 - Conference paper
AN - SCOPUS:85125069825
T3 - Proceedings - Euro PM2020 Congress and Exhibition
BT - Proceedings - Euro PM2020 Congress and Exhibition
PB - European Powder Metallurgy Association (EPMA)
T2 - European Powder Metallurgy Congress and Exhibition, Euro PM 2020
Y2 - 5 October 2020 through 7 October 2020
ER -