Researchers at the University of Massachusetts Amherst and the Georgia Institute of Technology have 3D printed a dual-phase, nanostructured high-entropy alloy that exceeds the strength and ductility of other state-of-the-art additively manufactured materials, which could lead to higher-performance components for applications in aerospace, medicine, energy and transportation. The work, led by UMass Mechanical & Industrial Engineering Assistant Professor Wen Chen & Georgia Tech Mechanical Engineering Professor Ting Zhu, is published online by the journal Nature. Over the past 15 years, high entropy alloys have become increasingly popular as a new paradigm in materials science. Comprised of five or more elements in near-equal proportions, they offer the ability to create a near-infinite number of unique combinations for alloy design. Traditional alloys, such as brass, carbon steel, stainless steel and bronze, contain a primary element combined with one or more trace elements. Additive manufacturing, also called 3D printing, has recently emerged as a powerful approach to material development. The laser-based 3D printing can produce large temperature gradients and high cooling rates that are not readily accessible by conventional routes. However, the potential of harnessing the combined benefits of additive manufacturing and high entropy alloys for achieving novel properties remains largely unexplored.Professor Chen and his team in the Multiscale Materials and Manufacturing Laboratory combined a high entropy alloy with a state-of-the-art 3D printing technique called laser powder bed fusion to develop new materials with unprecedented properties. Because the process causes materials to melt and solidify very rapidly as compared to traditional metallurgy, you get a very different microstructure that is far-from-equilibrium on the components created. This microstructure looks like a net and is made of alternating layers known as Face-Centered Cubic & Body-Centered Cubic nanolamellar structures embedded in micro scale eutectic colonies with random orientations. The hierarchical nanostructured HEA enables co-operative deformation of the two phases. This unusual microstructure’s atomic rearrangement gives rise to ultrahigh strength as well as enhanced ductility, which is uncommon, because usually strong materials tend to be brittle. Compared to conventional metal casting, researchers got almost triple the strength and not only didn’t lose ductility, but actually increased it simultaneously. For many applications, a combination of strength and ductility is key. Additional research partners on the paper include Texas A&M University, the University of California Los Angeles, Rice University, and Oak Ridge and Lawrence Livermore national laboratories.
Researchers at the University of Massachusetts Amherst and the Georgia Institute of Technology have 3D printed a dual-phase, nanostructured high-entropy alloy that exceeds the strength and ductility of other state-of-the-art additively manufactured materials, which could lead to higher-performance components for applications in aerospace, medicine, energy and transportation. The work, led by UMass Mechanical & Industrial Engineering Assistant Professor Wen Chen & Georgia Tech Mechanical Engineering Professor Ting Zhu, is published online by the journal Nature. Over the past 15 years, high entropy alloys have become increasingly popular as a new paradigm in materials science. Comprised of five or more elements in near-equal proportions, they offer the ability to create a near-infinite number of unique combinations for alloy design. Traditional alloys, such as brass, carbon steel, stainless steel and bronze, contain a primary element combined with one or more trace elements. Additive manufacturing, also called 3D printing, has recently emerged as a powerful approach to material development. The laser-based 3D printing can produce large temperature gradients and high cooling rates that are not readily accessible by conventional routes. However, the potential of harnessing the combined benefits of additive manufacturing and high entropy alloys for achieving novel properties remains largely unexplored.Professor Chen and his team in the Multiscale Materials and Manufacturing Laboratory combined a high entropy alloy with a state-of-the-art 3D printing technique called laser powder bed fusion to develop new materials with unprecedented properties. Because the process causes materials to melt and solidify very rapidly as compared to traditional metallurgy, you get a very different microstructure that is far-from-equilibrium on the components created. This microstructure looks like a net and is made of alternating layers known as Face-Centered Cubic & Body-Centered Cubic nanolamellar structures embedded in micro scale eutectic colonies with random orientations. The hierarchical nanostructured HEA enables co-operative deformation of the two phases. This unusual microstructure’s atomic rearrangement gives rise to ultrahigh strength as well as enhanced ductility, which is uncommon, because usually strong materials tend to be brittle. Compared to conventional metal casting, researchers got almost triple the strength and not only didn’t lose ductility, but actually increased it simultaneously. For many applications, a combination of strength and ductility is key. Additional research partners on the paper include Texas A&M University, the University of California Los Angeles, Rice University, and Oak Ridge and Lawrence Livermore national laboratories.
