EPM develops low cost ultra fine grained metals, nano-metals for structural applications
History

Throughout history the main goal of plastic deformation has been to change material shapes and sizes. Improvement of properties during deformation has remained a secondary issue. In the beginning of 1970, Dr. Segal was first to begin research and development on new metal working technologies specifically assigned to control materials structure. It was found that intensive, oriented and uniform simple shear deformation mode provides very strong and unusual structural effects. As a scientific concept, this direction may be traced to the early work of P. Bridgeman in 1930-1940 on phase transformation under high pressure and shear strains. Later, in 1950-1960, the so-called Bridgeman's anvils were applied in mechano-chemistry in USSR and other countries. However, this technique allows processing of very thin discs (typically, 10 mm diameter and 0.1 mm thickness), that presents purely an academic interest.

Dr. Segal’s research at the Physical-Technical Institute in Minsk, Belarus was oriented towards practical industrial applications. However, the work was closed for publication and only a few papers on the subject were published during the period from 1970 through the 1990’s despite an extensive amount of work. During this time, significant efforts were spent on the technical and engineering aspects of the new technology including many possible applications, processing concepts, equipment and tooling.

One new deformation technique, equal channel angular extrusion (ECAE), was invented in 1972. Presently, ECAE is the most well known technique for achieving severe plastic deformation (SPD). In many publications, the process of ECAE is considered the leading candidate for commercialization. The first industrial rolling mill for continuous ECAE was built in 1976. New structural effects of intensive simple shear deformation were discovered including (i) structure refinement to sub-micron, and even nano scale; (ii) geometrical control of grain size, phases, precipitates; (iii) control of texture; (iiii) healing of 3-dimensional defects such as pores, voids and cavities; (iiiii) consolidation and bonding of powders and particulate material, etc. Anomalous and unusual changes of mechanical properties (combination of extremely high strength and good ductility), physical properties (for magnets, superconductors, elinvar and invar alloys) and technological properties (enhanced superplasticity) were also detected.

By the middle of 1980’s, research and development on ECAE in the USSR was close to being transferred to volume production for some applications. However, this work was not completed and related information was not published. After the technology was introduced to the west in the 1990’s, the process was mainly associated with the refinement of material structure. The growing interest in nano technology generated significant activity and research on structural evolution and material characterization as a result of SPD in many National Laboratories and Universities in the USA, Japan, Korea, Germany, France, Britain, Russia, Austria, Spain, and Italy and extensive information can be found in scientific literature. Presently more than 1800 papers have been published all over the world and many International Conferences held on SPD. Unfortunately, this is mostly academic activity and has not been supported by corresponding progress in engineering and technological development. This fact is made obvious by the tremendous difference between numerous scientific publications and just a few related patents. Most scientists continue to work with a small-scale samples and research oriented tooling. Consequently, despite many promises, the technology remains far from industrial applications, resulting in sometimes skeptical reviews. In contrast to this situation, Dr. Segal’s long-term, hands-on, and creative activity in the field presents substantial advantages in the practical realization of the SPD technology. This is made clearly evident by the licensing of his patents to Honeywell and the first, still unique commercialization of large scale ECAE products, in this case for sputtering targets. With the advantage of this extensive experience and pioneering effort, along with further evolution on SPD, EPM is in an exceptional position for further and broad commercialization of this technology.


 

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