Science Daily August 3, 2022
The additive manufacture of metal alloys by laser powder bed fusion (L-PBF) involves large temperature gradients and rapid cooling which enables microstructural refinement at the nanoscale to achieve high strength. However, high-strength nanostructured alloys produced by laser additive manufacturing often have limited ductility. A team of researchers in the US (UMass Amherst, Georgia Institute of Technology, Texas A&M, Oak Ridge National Laboratory, Rice University, Lawrence Livermore National Laboratory, UCLA) used L-PBF to print dual-phase nanolamellar high-entropy alloys (HEAs) of AlCoCrFeNi that exhibit a combination of a high yield strength of about 1.3 gigapascals and a large uniform elongation of about 14%. The high yield strength stems from the strong strengthening effects of the dual-phase structures that consist of alternating face-centered cubic and body-centered cubic nanolamellae; the body-centred cubic nanolamellae exhibit higher strengths and higher hardening rates than the face-centred cubic nanolamellae. The mechanistic insights into the deformation behaviour of additively manufactured HEAs have broad implications for the development of hierarchical, dual- and multi-phase, nanostructured alloys with exceptional mechanical properties…read more. TECHNICAL ARTICLEÂ
Microstructure of AM AlCoCrFeNi2.1 EHEA. Credit: Nature (2022) 03 August 2022Â