September_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 | S E P T E M B E R 2 0 2 0 1 2 PROCESS TECHNOLOGY NEW DESIGN FOR MIXING POWDER COMPOSITES Researchers from South Ural State University, Russia, developed a new method for creating powder met- al composites while reducing waste and improving the quality of electrical products. The process is expected to in- crease the economic efficiency of pro- duction by 30%. The scientists introduced a new design for a mixing machine that makes composite powder based on graphito- plast compositions and coke pitch. The new machine and associated method produce a high-quality blend and in- crease material use up to 98%. The nov- el method improves the quality of fin- ished raw materials for the subsequent pressing process and could reduce waste in the fields of nuclear energy, metallurgy, electric transport, as well as the aviation and space industries. The teamof scientists believes that companies involved in the production of mixing machines might be interested in these developments, as they increase the efficiency of the equipment due to less waste when mixing, improve the quality of the finished blend, and sim- plify the design of mixing machines. In the future, the researchers plan to cre- ate high-entropy powder blends, which could be useful in powder metallurgy and additive manufacturing applica- tions. www.susu.ru/en. CREATING 3D HETEROSTRUCTURED MATERIALS In collaboration with Iowa State University researchers, scientists from the DOE’s Ames Laboratory developed a new approach for generating layered, heterostructured solids that could open new avenues for electronic and ener- gy applications. These materials, com- posed of layers of dissimilar building blocks, display unique electronic trans- port and magnetic properties that are governed by quantum interactions be- tween their structurally different build- ing blocks. The technique for making them is simple yet counterintuitive: It involves smashing the pristine materials to build new ones. Called mechanochemistry, the technique uses ball milling to take apart structurally incommensurate solids—ones that do not have match- ing atomic arrangements—and re- assembles them into unique 3D “misfit” hetero-assemblies. As one example, the team worked with metal chalcogenides, which are of- ten unique in their properties and uses. They can display significant electron transport behaviors ranging from com- plete lack of electrical conductivity to superconductivity, photoelectric and thermoelectric properties, mechanical pliability, and perhaps most important, the ability to form stable 2D monolay- ers, 3D heterostructures, and other na- no-scaled quantummaterials. Typically, these complex materi- als, especially ones with the most un- usual structures and properties, are made using two different synthetic ap- proaches—top-down synthesis and the broadly defined bottom-up synthesis. The Ames team combined these two methods into one mechanochemical process that simultaneously exfoliates, disintegrates, and recombines start- ing materials into new heterostructures even though their crystal structures do not fit each other well. Theoretical cal- culations, supported by the results of x-ray diffraction, scanning transmission electron microscopy, Raman spectros- copy, electron transport studies and, for the first time ever, solid state nucle- ar magnetic resonance experiments, explained the mechanismof the reorga- nization of precursor materials. These calculations also help explain the driv- ing forces behind the formation of novel 3D heterostructures during mechanical processing. ameslab.gov, iastate.edu. Newmethods for the development of powder composites are e icient while also reducing waste. Courtesy of Pixabay/ CC0 Public Domain. Scientists at Ningbo Institute of Materials Technology and Engineering, China, developed a novel direct growth method of vertically orientated nanocavity arrays to generate plasmonic structural colors, which feature wide gamut, improved color saturation, excellent stability in ambient condition, and mass-production scalability. english.nimte.cas.cn. BRIEF Plasmonic structural color sample.