Prof. Emeritus Elazar Y. Gutmanas

Elazar Y. Gutmanas

  • M.Sc. 1962 (Leningrad/St. Petersburg Polytechnic Institute)
  • Ph.D. 1970 (Institute of Solid State Physics, Cherngolovka, Moscow District)
Prof. Gutmanas immigrated from the U.S.S.R. and joined Technion’s Department of Materials Science & Engineering in 1974. In the U.S.S.R. he worked in the Institute of Solid State Physics of the U.S.S.R. Academy of Sciences, investigating dislocation mobility and mechanisms of plastic deformation. In 1985-1989 he acted as a Director of the Materials Eng. Center. He was a Visiting Professor at Drexel University in 1982-1983 and in 1989/90, and a Visiting Scientist at Max-Planck Institute, Stuttgart in 1979 and 1990. Techniques were developed which enabled the analysis of mechanisms of dislocation mobility from the change of the slope of the deformation curve at a fixed time, when the physical state of the material is changed. This relates to SN transitions for superconductive materials, to change of electronic state in illuminated semiconductors or ionic crystals, leading to photoplastic effect, and to pulse loading (stress-jump) and pulse heating (temperature-jump) methods, used for thermal activation analysis of plastic deformation. A near-net-shape processing method – Cold Sintering/High Pressure Consolidation of powders at ambient temperature was developed. Plastic deformation of powder particles under high pressure (up to 3 GPa) results in densities close to the theoretical and chemical bonding at the freshly formed oxide-free interfaces. Calculations show that shear stresses developed in the gradient of high pressure are sufficiently high to generate dislocations in practically all metals. Due to its non-equilibrium nature, cold sintering offers great potential for the development of alloys and materials that cannot be produced by conventional methods, e.g. metastable and nanocrystalline materials. Cold sintering was successfully used for creating advanced wear resistant metal-ceramic composites and, recently, for creating different classes of nanocomposite materials such as metal-ceramic, cermet and ceramic-polymer materials. Basing on cold sintering, novel reactive processing routes were developed for the synthesis of intermetallics, metal alloys and composites with fine submicron-scale microstructures. These processes include solid state displacement reactions in the blends of ultrafine metal and ceramic powders, reactions via super-transient liquid phase and combustion synthesis (Self-propagating High-Temperature Synthesis – SHS). For the first time, dense ceramic-matrix, intermetallic-matrix and interpenetrating phase composite parts were produced by pressure-assisted Thermal Explosion (a volumetric mode of SHS), employing an original Reactive Forging method (developed together with Dr. I. Gotman). All the developed processes offer substantial energy savings due to the use of high pressure instead of high temperature (as in Cold Sintering), and/or of materials’ own energy liberated in exothermic reactions (as in Reactive Forging). An original method for the coating of monolithic ceramics, particles and fibers (SiC, Si3N4, B4C, SiO2, diamond, etc.), as well as metals and alloys (Ti, steel, Co-Cr) – Powder Immersion Reaction Assisted Coating (PIRAC) was developed (together with Dr. I. Gotman). PIRAC is a non-line-of-sight reactive diffusion process yielding compound or solid solution protective coatings with gradient composition and properties. In addition, PIRAC coatings boast excellent adhesion to the substrate (as compared to both PVD and CVD coatings).