May/June_AMP_Digital

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 | M A Y / J U N E 2 0 1 8 8 METALS | POLYMERS | CERAMICS Outokumpu Long Products, Finland, won a contract to supply more than 2500 metric tons of stainless steel rebar to the Rodanthe Bridge project in North Carolina. The 2.4-mile bridge will ensure safe and reliable passage for travelers as well as provide better traffic flow. The bridge will enter service in 2020. outokumpu.com/rebar . Olympic Steel Inc., Cleveland, a national metals service center, acquired the assets of Berlin Metals LLC, Hammond, Ind. Founded in 1967, Berlin Metals is one of the largest North American service centers for processing and distributing prime tin mill prod- ucts and stainless steel strip in slit coil form. The company also supplies coated steels in coil form, including galvanized, light gauge cold-rolled sheet and strip for building products, automotive, and specialized industrial markets. olysteel.com . Wall Colmonoy, Madison Heights, Mich., is celebrating its 80th anniversary as a global materials engineering group that manufactures advanced metal coatings and compo- nents. Established in 1938 by Albert F. Wall, the company now has 500 employees with offices and manufacturing facilities in the U.S. and U.K. wallcolmonoy.com . BRIEFS PUTTING MUSCLE INTO SMART MATERIAL Engineers at Iowa State University, Ames, developed a smart and respon- sive rubbery material that stiffens by up to 300% when mechanically stressed, like working out a muscle. In lab tests, mechanical stresses transformed a flexible strip of the material into a hard composite that can support 50 times its own weight. The new material does not require outside energy sources such as heat, light, or electricity to change its properties. The researchers found a simple, low-cost way to produce particles of undercooled metal. The tiny particles— 1 to 20 millionths of a meter across— are created by exposing droplets of melted metal to oxygen, creating an oxidation layer that coats the droplets and stops the liquid metal from turning solid. They also found ways to mix the liquid-metal particles with a rubbery elastomer material without breaking the particles. When this hybrid mate- rial is subject to mechanical stresses— pushing, twisting, bending, or squeez- ing—the liquid-metal particles break open. The metal flows out of the oxide shell, fuses together, and solidifies. In this case, the liquid-metal par- ticles contain Field’s metal, an alloy of bismuth, indium, and tin. But the engi- neers say other metals will also work. Tuning could involve changing the met- al, the particle sizes, or the soft materi- al. The engineers say the new material could be used in medicine to support delicate tissues or in industry to pro- tect valuable sensors. There are also potential uses in soft and bio-inspired robotics or reconfigurable and wear- able electronics. Iowa State University Research Foundation is working to pat- ent the material, which is available for licensing. iastate.edu. NEW ALUMINUM ALLOYS FOR ENGINES Oak Ridge National Laboratory (ORNL), Tenn., partnered with FCA US LLC, Auburn Hills, Mich., and casting manufacturer Nemak, Mexico, to devel- op a new cast aluminum alloy for en- gine cylinder heads, which could lead to more fuel-efficient internal combus- tion engines. Using neutron diffraction at ORNL’s Spallation Neutron Source, residual stress levels of new materials and existing alloys can be compared. From left, a flexible strip of the new smart material, a flexible strip that stiffened when twisted, and a flexible strip transformed into a hard composite that can hold up a weight. Courtesy of Christopher Gannon.