Additive Manufacturing of CrFeNiTi Multi-Principal Element Alloys.

Area of Science:

• Materials Science
• Metallurgy
• Additive Manufacturing

Background:

• High entropy alloys (HEAs) and multi-principal element alloys (MPEAs) represent a novel research field with incomplete knowledge.
• Fabricating diverse HEA/MPEA material libraries is challenging.
• Additive manufacturing (AM) offers a promising route for rapid HEA/MPEA sample production via melting or sintering.

Purpose of the Study:

• To investigate the fabrication of CrFeNiTi MPEA samples using laser powder-bed fusion (PBF-LB).
• To compare PBF-LB with solid-state sintering for MPEA production.
• To analyze the relationship between processing parameters, composition, and microstructure.

Main Methods:

• Fabrication of CrFeNiTi MPEA samples using laser powder-bed fusion (PBF-LB).
• Solid-state sintering of mechanically alloyed powder feedstock used as a benchmark.
• Analysis of micro-hardness and local chemical composition variations.

Main Results:

• Dense CrFeNiTi MPEA samples were successfully fabricated within a volumetric energy density (VED) range of 50–83 J/mm³.
• An average micro-hardness of 965 HV0.1 was recorded in defect-free sections.
• Titanium evaporation at higher VED led to reduced C14_Laves phase fraction and influenced micro-hardness.

Conclusions:

• PBF-LB is an effective method for producing dense MPEA samples with controlled properties.
• VED significantly impacts titanium content and Laves phase formation, affecting alloy hardness.
• Understanding these correlations is crucial for designing advanced MPEAs.