8 A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 2 2 scientists demonstrated the relation on alloys of aluminum, cobalt, copper, iron, nickel, steel, and refractory alloys used in a large variety of key engineering applications. “What is remarkable is that the nanoscale deformation events that appear after a single deformation cycle correlate with the fatigue strength that inform the life of a metallic part under a large number of cycles,” Stinville says. “Discovering this correlation is like having access to a unique deformation fingerprint that can help us rapidly predict the fatigue life of metallic parts.” illinois.edu. CRYSTAL FORMATION AT THE ATOMIC SCALE A team of international scientists is using atomic scale imaging to visualize the crystallization process like never before. Studying crystal formation at the surface, researchers from the University of Washington, Seattle, Pacific Northwest National Laboratory, Richland, Wash., and Durham University, U.K., used the imaging technology to observe the nucleation of an TESTING | CHARACTERIZATION METALLIC DEFORMATION FINGERPRINTS Capturing and predicting the strength of metallic materials subjected to cycling loading, or fatigue strength, just became a lot quicker. A discovery by researchers from the University of Illinois Urbana-Champaign shows how engineers can use automated high-resolution electron imaging to capture nanoscale deformation events that lead to metal failure and breakage at the origin. The new method helps scientists to rapidly predict the fatigue strength of any alloy and design new materials for engineering systems subject to repeated loading for medical, transportation, safety, energy, and environmental applications. Fatigue of metals and alloys—such as the repeated bending of a metal paperclip that leads to its fracture—is the root cause of failure in many engineering systems, according to the researchers. Defining the relationship between fatigue strength and microstructures is challenging because metallic materials display complex structures, with features ranging from nanometer to centimeter scale. The team is the first to uncover the relationship between surface-level events and fatigue predictions in metals. Using automated high-resolution digital image correlations, collected by the scanning electron microscope, the researchers’ technique compiles and compares a series of images recorded during deformation, explains lead researcher Jean-Charles Stinville. The Ametek Land, U.K., is celebrating 75 years of building monitors and analyzers for industrial infrared noncontact temperature measurement, combustion efficiency, and environmental pollutant emissions. Founded in 1947, Land Instruments Intl. Ltd. was acquired by Ametek Inc. in 2006. The company serves the steelmaking, glassmaking, minerals processing, hydrocarbon processing, and thermal power generation industries. ametek-land.com. Sakor Technologies Inc., Owosso, Mich., supplied an accelerated belt aging stand to Ford Motor Company for use in belt noise testing. Ford will use the stand to test new belt materials and designs to evaluate how they are likely to perform in an engine over time. sakor.com. BRIEFS Professors Jean-Charles Stinville and Marie Charpagne captured nanoscale deformation events at the origin of metal failure. Courtesy of Fred Zwicky. In situ atomic force microscopy image sequence from a movie showing the growth and coalescence of clusters to create an extended film. Courtesy of Fred Zwicky.
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