In the United States, about 20 percent of our electricity and almost 70 percent of the electricity from emission-free sources, including renewable technologies and hydroelectric power plants, is supplied by nuclear power. Along with power generation, many of the world's nuclear facilities are used for research, materials testing, or the production of radioisotopes for the medical industry. The service life of structural and functional material components in these facilities is therefore crucial for ensuring reliable operation and safety.
Scientists at Lawrence Berkeley National Laboratory and the University of California at Berkeley conducted compression tests of copper specimens irradiated with high-energy protons, designed to model how damage from radiation affects the mechanical properties of copper. By using a specialized in situ mechanical testing device in a transmission electron microscope at the National Center for Electron Microscopy, the team could examine -- with nanoscale resolution -- the localized nature of this deformation. (Scales in nanometers, millionths of a meter.) Credit: Minor et al, Lawrence Berkeley National Laboratory
Now scientists at Berkeley Lab, the University of California at Berkeley, and Los Alamos National Laboratory have devised a nanoscale testing technique for irradiated materials that provides macroscale materials-strength properties. This technique could help accelerate the development of new materials for nuclear applications and reduce the amount of material required for testing of facilities already in service.
"Nanoscale mechanical tests always give you higher strengths than the macroscale, bulk values for a material. This is a problem if you actually want use a nanoscale test to tell you something about the bulk-material properties," said Andrew Minor, a faculty scientist in the National Center for Electron Microscopy (NCEM) and an associate professor in the materials science and engineering department at UC Berkeley. "We have shown you can actually get real properties from irradiated specimens as small as 400 nanometers in diameter, which really opens up the field of nuclear materials to take advantage of nanoscale testing."
In this study, Minor and his colleagues conducted compression tests of copper specimens irradiated with high-energy protons, designed to model how damage from radiation affects the mechanical properties of copper. By using a specialized in situ mechanical testing device in a transmission electron microscope at NCEM, the team could examine — with nanoscale resolution — the nature of the deformation and how it was localized to just a few atomic planes.
Three-dimensional defects within the copper created by radiation can block the motion of one-dimensional defects in the crystal structure, called dislocations. This interaction causes irradiated materials to become brittle, and alters the amount of force a material can withstand before it eventually breaks. By translating nanoscale strength values into bulk properties, this technique could help reactor designers find suitable materials for engineering components in nuclear plants.
"This small-scale testing technique could help extend the lifetime of a nuclear reactor," said co-author Peter Hosemann, an assistant professor in the nuclear engineering department at UC Berkeley. "By using a smaller specimen, we limit any safety issues related to the handling of the test material and could potentially measure the exact properties of a material already being used in a 40-year-old nuclear facility to make sure this structure lasts well into the future."
Minor adds, "Understanding how materials fail is a fundamental mechanistic question. This proof of principle study gives us a model system from which we can now start to explore real, practical materials applicable to nuclear energy. By understanding the role of defects on the mechanical properties of nuclear reactor materials, we can design materials that are more resistant to radiation damage, leading to more advanced and safer nuclear technologies."
A paper reporting this research titled, "In situ nanocompression testing of irradiated copper," appears in Nature Materials and is available to subscribers online. Co-authoring the paper with Minor and Hosemann were Daniel Kiener and Stuart Maloy. Portions of this work at the National Center for Electron Microscopy were supported by DOE's Office of Science.
Lawrence Berkeley National Laboratory addresses the world's most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab's scientific expertise has been recognized with 12 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy's Office of Science. For more, visit www.lbl.gov.
Aditi Risbud | EurekAlert!
How nanoscience will improve our health and lives in the coming years
27.10.2016 | University of California - Los Angeles
3-D-printed structures shrink when heated
26.10.2016 | Massachusetts Institute of Technology
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Materials Sciences
27.10.2016 | Physics and Astronomy
27.10.2016 | Life Sciences