ADVANCED MATERIALS & PROCESSES | NOVEMBER/DECEMBER 2024 5 RESEARCH TRACKS AI AWARD TURBOCHARGES TURBOMACHINERY A new award from the U.S. Defense Advanced Research Projects Agency (DARPA) is bringing together researchers from Massachusetts Institute of Technology, Carnegie Mellon University, and Lehigh University under the Multi- objective Engineering and Testing of Alloy Structures (METALS) program. The goal is to develop design tools that optimize shape and compositional gradients in multi-material structures that complement new high-throughput materials testing techniques. A special focus area is the bladed disk (blisk) geometry found in most turbomachinery including jet and rocket engines. “This project could have important implications across a wide range of aerospace technologies. Insights from this work may enable more reliable, reusable rocket engines that will power the next generation of heavy-lift launch vehicles,” says principal investigator Zachary Cordero of MIT. “This project merges classical mechanics analyses with cutting-edge generative AI design technologies to unlock the plastic reserve of compositionally graded alloys allowing safe operation in previously inaccessible conditions.” Different locations in blisks require different thermomechanical properties and performance, such as resistance to creep, low cycle fatigue, and the need for high strength. Large-scale production also must consider cost and sustainability metrics such as sourcing and recycling of alloys in the design. Although a one-material approach may be optimal for a singular location in a com- ponent, it could leave other locations exposed to failure or may require a critical material to be carried throughout an entire part when it might only be needed in a specific location. With the rapid advancement of additive manufacturing (AM) processes that are enabling voxel-based composition and property control, the team sees that unique opportunities for advanced performance in structural components are now possible. The expertise of the researchers includes hybrid integrated computational materials engineering and machine learning-based ma- terials and process design, precision instrumentation, metrology, topology optimization, deep generative modeling, additive manufacturing, materials characterization, thermostructural analysis, and turbomachinery. mit.edu. NEW WORLD RECORD FOR X-RAYS During a collaboration with EPFL Lausanne, ETH Zurich, and the University of Southern California, View inside a state-of-the-art computer chip. Courtesy of Tomas Aidukas, PSI. researchers at the Paul Scherrer Institute (PSI), Switzerland, used x-rays to look inside a microchip with higher precision than ever before. The image resolution of four nanometers achieves a new world record. The high-resolution 3D images of the kind they produced are expected to enable advances in everything from information technology to the life sciences and materials science. Instead of using lenses, the scientists used ptychography, in which a computer combines many individual images to create a single, high-resolution picture. In this technique, the x-ray beam is not focused on a nanometer scale; instead, the sample is moved on a nanometer scale. Shorter exposure times and an optimized algorithm were key to significantly improving on the world record they themselves set in 2017. For their experiments, the researchers used x-rays from the Swiss Light Source at PSI. The new ptychographic technique is a basic approach that can be used at similar research facilities. The method is not confined to microchips, but is also well suited to other samples, for example in materials science or life sciences. www.psi.ch. A student in Zachary Cordero’s aerospace lab works with AM equipment. Courtesy of Jake Belcher/MIT.
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