The Press-Dispatch
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A-10 Local Wednesday, Januar y 31, 2018 The Press-Dispatch Call 317-650-4086 (cell) Call Today! Edith Norrington turned 100 YEARS young on January 30 Please join Edith, family and friends for cake, ice cream and refreshments as we celebrate this milestone occasion on Sunday, February 4 from 2 p.m. to 4 p.m. at Otwell Methodist Church located at 10055 East Washington Street, Otwell. Cards Only No Gi s Please. 100 100 100 100 100 100 100 100 100 100 100 100 100 100 HAPPY 90 th FEBRUARY 3, 1928 Send a card to: 840 Lakewood Rd., Petersburg, IN 47567 Ruby Kirk By Emil Venere Purdue News Service venere@purdue.edu Researchers have demon- strated how to create a su- per-strong aluminum alloy that rivals the strength of stainless steel, an advance with potential industrial ap- plications. "Most lightweight alu- minum alloys are soft and have inherently low mechan- ical strength, which hinders more widespread industri- al application," said Xing- hang Zhang, a professor in Purdue University's School of Materials Engineering. "However, high-strength, lightweight aluminum alloys with strength comparable to stainless steels would revo- lutionize the automobile and aerospace industries." New research shows how to alter the microstruc- ture of aluminum to impart greater strength and ductil- ity. Findings were detailed in two new research papers. The work was led by a team of researchers that includ- ed Purdue postdoctoral re- search associate Sichuang Xue and doctoral student Qiang Li. The most recent paper was published online Jan. 22 in the journal Advanced Materials. The earlier paper was published in November in the journal Nature Com- munications. The new high-strength aluminum is made possi- ble by introducing "stack- ing faults," or distortions in the crystal structure. While these are easy to produce in metals such as copper and silver, they are difficult to introduce in aluminum be- cause of its high "stacking fault energy." A metal's crystal lattice is made up of a repeating se- quence of atomic layers. If one layer is missing, there is said to be a stacking fault. Meanwhile, so-called "twin boundaries" consisting of two layers of stacking faults can form. One type of stack- ing fault, called a 9R phase, is particularly promising, Zhang said. Zhang aluminum Pur- due postdoctoral research associate Sichuang Xue, at left, and doctoral student Qiang Li, prepare a sam- ple for research to create super-strong aluminum al- loys. (Purdue University image/Marshall Farthing) Download image "It has been shown that twin boundaries are diffi- cult to be introduced into aluminum. The formation of the 9R phase in alumi- num is even more difficult because of its high stacking fault energy," Zhang said. "You want to introduce both nanotwins and 9R phase in nanograined aluminum to increase strength and duc- tility and improve thermal stability." (A YouTube video is available at https://you- tu.be/Y3dYq-N4xSY ) Now, researchers have learned how to readily achieve this 9R phase and nanotwins in aluminum. "These results show how to fabricate aluminum al- loys that are comparable to, or even stronger than, stain- less steels," he said. "There is a lot of potential commer- cial impact in this finding." Xue is lead author of the Nature Communications paper, which is the first to report a "shock-induced" 9R phase in aluminum. Re- searchers bombarded ultra- thin aluminum films with ti- ny micro-projectiles of sil- icon dioxide, yielding 9R phase. "Here, by using a laser- induced projectile impact testing technique, we dis- cover a deformation-in- duced 9R phase with tens of nanometers in width," Xue said. The microprojectile tests were performed by a re- search group at Rice Uni- versity, led by professor Edwin L. Thomas, a co- author of the Nature Com- munications paper. A laser beam causes the particles to be ejected at a velocity of 600 meters per second. The procedure dramatically ac- celerates screening tests of various alloys for impact-re- sistance applications. "Say I want to screen ma- ny materials within a short time," Zhang said. "This method allows us to do that at far lower cost than other- wise possible." Li is lead author of the Advanced Materials paper, which describes how to in- duce a 9R phase in alumi- num not by shock but by in- troducing iron atoms into aluminum's crystal struc- ture via a procedure called magnetron sputtering. Iron also can be introduced into aluminum using other tech- niques, such as casting, and the new finding could po- tentially be scaled up for industrial applications. The resulting "nanot- winned" aluminum-iron al- loy coatings proved to be one of the strongest alu- minum alloys ever creat- ed, comparable to high- strength steels. "Molecular-dynamics simulations, performed by professor Jian Wang's group at the University of Nebras- ka, Lincoln, showed the 9R phase and nanograins result in high strength and work- hardening ability and re- vealed the formation mecha- nisms of the 9R phase in alu- minum," Zhang said. "Un- derstand new deformation mechanisms will help us de- sign new high strength, duc- tile metallic materials, such as aluminum alloys." Zhang aluminum2 A sam- ple is readied for analysis us- ing a transmission electron microscope. (Purdue Uni- versity image/Marshall Far- thing) Download image One potential application might be to design wear- and corrosion-resistant alu- minum alloy coatings for the electronics and automobile industries. The research was mainly funded by U.S. Department of Energy's Office of Basic Energy Sciences, Materials Left: Zhang aluminum Pur- due postdoctor- al research as- sociate Sichuang Xue, at left, and doctoral student Qiang Li, pre- pare a sample for research to cre- ate super-strong aluminum alloys. Purdue University photo Below: A sam- ple is readied for analysis us- ing a transmis- sion electron mi- croscope. Purdue University photo New research yields super-strong aluminum alloy Science and Engineering Division. The researchers have filed a patent applica- tion through the Purdue Re- search Foundation's Office of Technology Commercial- ization. The transmission elec- tron microscopy work for the research was support- ed by a new FEI Talos 200X microscope facility direct- ed by Haiyan Wang, Pur- due's Basil S. Turner Pro- fessor of Engineering; and the "in situ micropillar com- pression" work in scanning electron microscopes was supported by Purdue's Life Science Microscopy Facili- ty, led by Christopher J. Gil- pin, director of the facility. These advanced microsco- py facilities were made pos- sible with support from Pur- due's Office of the Executive Vice President for Research and Partnerships. The team included re- searchers from Purdue's School of Materials Engi- neering, Department of Materials Science and Na- noEngineering at Rice Uni- versity, the Department of Engineering Physics at the University of Wisconsin- Madison, State Key Lab of Metal Matrix Composites, the School of Materials Sci- ence and Engineering at Shanghai Jiao Tong Univer- sity, Department of Materi- als Science and Engineer- ing at China University of Petroleum, California In- stitute of Technology, Lou- isiana State University and the University of Nebraska- Lincoln. A complete listing of co-authors is available in the abstracts.