Please note that the program is published in Central European Summer Time (CEST).

Back to overview

Lecture

WEB L-PBF-Microstructures of Steel Alloys and Nickel Base Alloys

Wednesday (23.09.2020)
17:35 - 17:50 S: Structural Materials 1
Part of:


In this work, different cast alloys (austenitic steel 1.4408, duplex steel 1.4517, nickel base alloy 6.4856 and nickel-base-copper alloy 6.4356) were gas atomized and printed in the L-PBF-process. Their microstructures were investigated and compared using two different scanning strategies and heat treatments. Calphad and Scheil-Gulliver numeric simulations for non-equilibrium solidification will be presented. Equiaxed, columnar and epitaxial structures and precipitates were characterized with various analytical and microscopic methods.

Precipitates, melt lines and other microstructural phases under the following process stages were analyzed:

• Cast material

• Powder particles for L-PBF

• LPBF microstructure

• LPBF microstructure after post heat treatment

• Tensile test samples

Correlations between microstructure and tensile properties were established. Although the strength was only mildly affected by varying the scanning parameters, the ductility was significantly influenced. Post-heat treatments had different effects on the ductility. Compared to the cast material, the additive samples achieved an improvement in mechanical properties in all cases.


Methods of investigation: REM, EDS, EBSD, LOM, tensile tests, Calphad simulation, Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), inert gas fusion (IGF).

 

Speaker:
Dr. Iris Raffeis
RWTH Aachen University
Additional Authors:
  • Frank Adjei-Kyeremeh
    RWTH Aachen University
  • Dr. Uwe Vroomen
    RWTH Aachen University
  • Dr. Elmar Westhoff
    Otto Junker GmbH
  • Andreas Bührig-Polaczek
    RWTH Aachen University