Microstructure of NiAl-Ta-Cr in situ alloyed by induction-assisted laser-based directed energy deposition

• DOI: 10.1016/j.matdes.2024.112667
• Publication Date: 2024-01-18T11:56:26Z
• Authors: Michael Müller; Stefan Enghardt; Martin Kuczyk; Mirko Riede; Elena López; Frank Brueckner; Axel Marquardt; Christoph Leyens
• Keywords: Intermetallics; Additive manufacturing; Nickel aluminide; 02 engineering and technology; Direct energy deposition; In situ alloying; Metallurgy and Metallic Materials; TA401-492; Manufacturing, Surface and Joining Technology; Metallurgi och metalliska material; Bearbetnings-, yt- och fogningsteknik; Advanced materials; 0210 nano-technology; Materials of engineering and construction. Mechanics of materials

The development of new high temperature materials for coatings as well structural components is an important topic to contribute a higher efficiency and sustainability e.g. gas turbine engines. One promising class are NiAl-based alloys. Within this study, the microstructure microhardness NiAl-Ta-Cr alloys with varying Cr Ta content were investigated. Graded specimens fabricated by laser-based directed energy deposition utilizing in situ alloying approach mixing elemental pre-alloyed NiAl powder. Thermodynamic calculations performed design alloy compositions beforehand. Inductive preheating substrate was used counter challenge cracking due brittleness. results show that decreases increasing temperature. However, even at 700 °C, cannot be fully eliminated. Scanning electron microscopy, X-ray diffraction backscatter revealed formation phases B2-NiAl, A2-Cr C14-NiAlTa within NiAl-Ta NiAl-Cr For compositions, deviations regarding phase between calculation experiment observed. Maximum hardness values achieved systems eutectic 14 at.-% maximum above 900 HV0.1.