By U.S. Department of Energy January 10, 2024Innovative high-entropy alloys, crafted through laser-based additive production, offer unmatched strength and ductility for commercial applications. These brand-new materials, evaluated with advanced methods, promise enhanced performance in extreme conditions. Credit: SciTechDaily.comLaser-based additive production produces high-entropy alloys that are stronger and less most likely to fracture.Researchers make a kind of material called durable high-entropy alloys (HEAs) by integrating several elemental metals. HEAs have potential usages in applications involving serious wear and tear, severe temperatures, radiation, and high stress.They can be made using 3D printing, likewise referred to as additive manufacturing (AM), but this generally results in bad ductility. This suggests 3D-printed HEAs are hard to form and do not deform, or stretch, enough under loads to avoid fractures.Scientists have now utilized laser-based AM to form HEAs that are stronger and a lot more ductile. They used neutron and X-ray scattering and electron microscopy to better understand the systems of these performance improvements.Potential Industrial Applications and Energy EfficiencyIndustry could one day use more powerful and more quickly shaped HEAs in manufacturing. To work in these applications, complicated and light HEA parts require improved resistance, reliability, and durability to fracturing.This would benefit consumers and market, for instance, by enabling the production of safer and more fuel-efficient vehicles, stronger products, and longer-lasting machinery. In addition, laser-based AM, in which lasers fuse powdered alloys into solid metal shapes, is highly energy effective. This makes it attractive for producing brand-new types of HEAs.Images of the 2 crystal structures (right) discovered in a high-entropy alloy (left) made by additive production. Credit: University of Massachusetts AmherstNano-Lamellae Structure and Mechanical PropertiesThe laser-based AM process produced nanometer-thick nano-lamellae (thin layers of plates) offering high strength, while the plates distinct edges permit a degree of slippage (ductility). The plates consist of rotating layers of face-centered cubic (FCC) crystal structures that average approximately 150 nanometers thick and body-centered cubic (BCC) crystal structures that average approximately 65 nanometers thick.The brand-new HEAs showed high yield strengths of about 1.3 gigapascals– exceeding the strongest titanium alloys. These HEAs likewise offer an elongation of about 14%, which is higher than other AM metal alloys provided the exact same yield strength. Elongation is a step of how much flexing a material can stand up to without breaking.Advanced Research Techniques and FacilitiesNeutron information from the Spallation Neutron Source, a Department of Energy (DOE) Office of Science user center at Oak Ridge National Laboratory (ORNL), allowed the scientists to examine the interior mechanical load sharing of the HEA samples while under strain.The researchers utilized an atom probe instrument at the Center for Nanophase Materials Sciences, likewise a DOE user center at ORNL, to capture in-depth 3D images of the microstructures and compositions, including rotating nano-lamellae layers.The stages of various annealed samples were studied using X-ray diffraction at the Advanced Photon Source, another DOE Office of Science user facility at Argonne National Laboratory.Reference: “Strong yet ductile nanolamellar high-entropy alloys by additive manufacturing” by Jie Ren, Yin Zhang, Dexin Zhao, Yan Chen, Shuai Guan, Yanfang Liu, Liang Liu, Siyuan Peng, Fanyue Kong, Jonathan D. Poplawsky, Guanhui Gao, Thomas Voisin, Ke An, Y. Morris Wang, Kelvin Y. Xie, Ting Zhu and Wen Chen, 3 August 2022, Nature.DOI: 10.1038/ s41586-022-04914-8This research study was performed at the Spallation Neutron Source, the Advanced Photon Source, and Center for Nanophase Materials Sciences, all of which are DOE Office of Science user facilities. Funding assistance for this work included the National Science Foundation, the University of Massachusetts Amherst, and the Laboratory Directed Research and Development program at Lawrence Livermore National Laboratory.
