(Press-News.org) A North Carolina State University researcher and colleagues have figured out a way to make an aluminum alloy, or a mixture of aluminum and other elements, just as strong as steel.
That's important, says Dr. Yuntian Zhu, professor of materials science and the NC State researcher involved in the project, because the search for ever lighter – yet stronger – materials is crucial to devising everything from more fuel-efficient cars to safer airplanes.
In a paper published in the journal Nature Communications, Zhu and his colleagues describe the new nanoscale architecture within aluminum alloys that have unprecedented strength but also reasonable plasticity to stretch and not break under stress. Perhaps even more importantly, the technique of creating these nanostructures can be used on many different types of metals.
Zhu says the aluminum alloys have unique structural elements that, when combined to form a hierarchical structure at several nanoscale levels, make them super-strong and ductile.
The aluminum alloys have small building blocks, called "grains," that are thousands of times smaller than the width of a human hair. Each grain is a tiny crystal less than 100 nanometers in size. Bigger is not better in materials, Zhu says, as smaller grains result in stronger materials.
Zhu also says the aluminum alloys have a number of different types of crystal "defects." Nanocrystals with defects are stronger than perfect crystals.
Now, Zhu plans on working on strengthening magnesium, a metal that is even lighter than aluminum. He's collaborating with the Department of Defense on a project to make magnesium alloys strong enough to be used as body armor for soldiers.
Zhu's colleagues on the Nature Communications paper are affiliated with the University of Sydney in Australia; the University of California, Davis; and Ufa State Aviation Technical University in Russia.
###
The Department of Materials Science and Engineering is part of NC State's College of Engineering.
Note: An abstract of the paper follows.
"Nanostructural hierarchy increases the strength of aluminium alloys"
Authors: Yuntian Zhu, North Carolina State University; Peter Liddicoat, Simon P. Ringer and Xiao-Zhou Liao, University of Sydney; Yonghao Zhao and Enrique J. Lavernia, University of California, Davis; Maxim Y. Murashkin and Rusian Z. Valiev, Ufa State Aviation Technical University
Published: Sept. 7, 2010, in Nature Communications
Abstract: Increasing the strength of metallic alloys while maintaining formability is an interesting challenge for enabling new generations of lightweight structures and technologies. In this paper, we engineer aluminium alloys to contain a hierarchy of nanostructures and possess mechanical properties that expand known performance boundaries – an aerospace-grade 7075 alloy exhibits a yield strength and uniform elongation approaching 1 GPa and 5%, respectively. The nanostructural architecture was observed using novel high-resolution microscopy techniques and comprises a solid solution, free of precipitation, featuring (i) a high density of dislocations, (ii) subnanometre intragranular solute clusters, (iii) two geometries of nanometre-scale intergranular solute structures and (iv) grain sizes tens of nanometres in diameter. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of super-strong materials with new regimes of property-performance space.
END
U.S. Department of Agriculture (USDA) researchers and their university colleagues have sequenced the majority of the genome of Meleagris gallopavo, the domesticated turkey, creating the first-ever turkey genome map. The nearly complete map could help growers to more efficiently produce bigger, meatier turkeys. The research is reported today in PLoS Biology, an online journal of the Public Library of Science.
Americans consume about 17.6 pounds of turkey per capita every year, and the U.S. produces nearly 6 billion pounds of turkey meat annually.
"Turkey is the fourth ...
For 70 years the world has mismanaged the common good of antibiotics. The result is a growing global burden of antibiotic resistance, threatening to take health care back to an era where ordinary infections might once again become fatal.
At a historic three day conference at Uppsala University, Sweden, 190 delegates representing 45 countries and many leading stake holders – civil society, academia, industry, governments, authorities, supranational organizations – agreed on Wednesday to turn a new page and move towards concerted action on antibiotic resistance.
"This ...
Researchers at the Johns Hopkins Bloomberg School of Public Health have developed new software that greatly improves the speed at which scientists can analyze RNA sequencing data. RNA sequencing is used to compare differences in gene expression to identify those genes that switched on or off when, for instance, a particular disease is present. However, sequencing instruments can produce billions of sequences per day, which can be time-consuming and costly to analyze. The software, known as Myrna, uses "cloud computing," an Internet-based method of sharing computer resources. ...
By integrating remote satellite imagery with revelations from door-to-door interviews, Stanford University geographer Eric Lambin and his colleagues are exploring the complex conditions that give rise to a broad range of land-use challenges – from the reforestation of Vietnam to the spread of Lyme disease in Belgium.
For decades, orbiting satellites have peered downward to gather information about the surface of the Earth, giving scientists an unprecedented view of the planet. Using this data, researchers have created maps of deforestation and other land-use changes over ...
Scientists are calling for more research on the possibility that some supposedly healthful plant-based antioxidants — including those renowned for their apparent ability to prevent cancer — may actually aggravate or even cause cancer in some individuals. Their recommendation follows a study in which two such antioxidants — quercetin and ferulic acid — appeared to aggravate kidney cancer in severely diabetic laboratory rats. The study appears in ACS' bi-weekly Journal of Agricultural and Food Chemistry.
Kuan-Chou Chen, Robert Peng, and colleagues note that vegetables, ...
Pullman, WA—September 8, 2010— Nutritional science and food marketing has become so sophisticated in recent decades that a trip to the supermarket can require a complete nutritional re-education. The average consumer needs to be on guard against preservatives, added fat, colorings, and calories, false advertising, and sophisticated but misleading labels. Although guidelines for the information of food labels have gotten a bad rap in recent years a new study published in the Journal of Consumer Affairs suggests that observing them may lead to weight loss, especially for ...
Twenty million medical scans and treatments are done each year that require radioactive isotopes, and scientists today described a global shortage of these life-saving materials that could jeopardize patient care and drive-up health care costs. They spoke at a symposium at one of the opening sessions of the 240th National Meeting of the American Chemical Society.
Medical isotopes are minute amounts of radioactive substances used to diagnose and treat a variety of diseases. Isotopes injected into the body can enable doctors to determine whether the heart has adequate ...
COLUMBUS, Ohio – Simply teaching people the facts about how to protect themselves from HIV may not be enough to prevent the spread of AIDS in Africa, a new study suggests.
Researchers found that villagers in Ghana who had higher levels of cognitive and decision-making abilities – not just the most knowledge -- were the ones who were most likely to take steps to protect themselves from HIV infection.
These cognitive abilities are what people develop through formal education, said Ellen Peters, lead author of the study and associate professor of psychology at Ohio State ...
Scientists today described development and successful initial tests on a substance that acts as a sunscreen for the microscopic spores of a fungus, brightening prospects for wider use of the fungus as a means of wiping out insect pests that attack food crops. "Our finding is especially important for the environment because improving the effectiveness of biological control treatments like this will help to reduce dependence on chemical pesticides," said team leader Robert W. Behle, Ph.D.
Behle explained that the fungus –– Beauveria bassiana –– shows great promise as a ...
The eyes may or may not be windows to the soul, as the old adage goes, but scientists are reporting evidence that a peek into the eyes of cattle may become the basis for a long-sought test to detect infection with the agent that causes Mad Cow Disease. That test could help prevent the disease from spreading in the food supply. A study on using the tell-tale glow given off by eyes infected with the Mad Cow agent appears in ACS' semi-monthly journal Analytical Chemistry.
Jacob Petrich and colleagues note that the human form of Mad Cow Disease is linked to eating beef from ...
