Prof. Nachum Frage
Image Item
Professor
Department :
Department of Materials Engineering
Room :
200
בנין בתי מלאכה - 60
Phone :
972-8-6472572
972-8-6472492
972-8-6479441
972-8-6461468
Email :
nfrage@bgu.ac.il
Office Hours :
Education
1970. M. Sc. in Electrometallurgy of Steels, Chelyabinsk Polytechnic Institute.
1974. Ph.D. in Electrometallurgy of Steels. Siberian Institute of Metallurgy, Novokuznetsk. "Interaction of titanium nitride with liquid metal and oxides systems" Advisor Prof. Gurevich Yu. G.
1989. D.Sc. (Dr. Hab.) in Powder Metallurgy and Composite Materials. Institute of Materials Science, Ukrainian Academy of Sc., Kiev. "Study of High Temperature Interaction of the Titanium Refractory Compounds (TiN, TiCx, TiCxNy) with Metal and Oxide Systems for Improving Ceramic Matrix and Metal Matrix Composites".
Research Interests
1. Metal-ceramic composites (MCC). Processing, microstructure and properties. Methods: infiltration of porous ceramic bodies with liquid metals and liquid phase sintering. Composition of MCC: TiC-Me, TiB2-Me, B4C-Me, Al2O3-Me (Me-steels, super-alloys, Ni, Co, Al, Mg).
2. Particulate reinforced metal matrix composites (MMC). Processing, microstructure and properties. Composition of MMC: Al - SiC, Al - Al2O3, Mg - SiC, Mg - Al2O3.
3. Thermodynamic analysis of the multicomponent and multiphase systems based on ceramic phases (carbides, nitrides, oxides) and metallic solutions over a wide temperature range.
4. Powder technology processing and phases interaction during manufacturing of steels, light alloys and composite materials
5. Heat and chemical treatment of steels and composite materials.
6. Manufacturing of special materials by powder metallurgical technology (e,g. Damascus steel).
Research Projects
1. Cavity sealing technique to be used in wafer Level Chip Scale Packaging (CSP) for Mems/Moems application with integrated cavity, Magnet MOEMS, 2001-2006
2. p-FEM for Class of Pressure Dependent Plastisity Models with Application to Cold Isostatic Pressure (CIP) Processes, GIF Research grant, 2003-2005,
3. Transparent armor ceramics, Ministry of Defense, 2005-2007, 300.000 NIS (with M.P. Dariel)
4.Thermochemistry and Dynamic Response of Reaction Bonded Metal-CeramicComposites, Israel Science Foundation, 2003-2006
5. Advanced method for ceramic sintering, Ministry of Defense, 2005-2008
6. Interaction between solid oxides and liquid metals, VATAT, 2005-2007
7. Precipitation kinetics in high strength steels, VATAT, 2006-2007.
8. High Pressure – High Temperature Synthesis and Properties Study of New Superhard Materials of the B-N-O System. Ministry of Science, Israel–Ukraine Foundation, 2006-2008
9. Retention of the nano-structure in bulk ceramics and ceramic composites, Ministry of Science, 2006-2009
Research Abstract
Our scientific activity is focused on two main areas. First the R&D of reaction bonded light composites for armor applications. Second, the R&D involved in the fabrications of polycrystalline transparent ceramics by means of the Spark Plasma Sintering (SPS) technology. The investigations are conducted in collaboration with Prof. Emeritus Moshe P. Dariel, Dr. S. Hayun, Dr. S.Kalabuchov, Dr. N.Sverdlov, Dr. H.Dilman, and several second degree master students were and are also actively involved in these two main areas of activity
Boron carbide and silicon carbide are most attractive materials for light armor application on account of their combination of elevated hardness (2800-3500 HV) and high Young’s modulus (400-450 GPa) values with the low density (2.52-3.22 g/cm3). This combination provides high ballistic efficiency. The "Reaction Bonding" approach is used for the fabrication of boron and silicon carbides based composites. In the process a green body made of a mixture of ceramic powders and carbon is infiltrated with molten silicon. The molten silicon reacts with the carbon and a final composite consists of continuous ceramic skeleton (SiC and B4C) and residual silicon. The main advantage of the reaction bonded is the low process temperature (~1500?C) and its drawback is related to the presence of the residual silicon that reduces the mechanical properties of the final composites. Our research group investigates the reaction between boron carbide and molten silicon, the nucleation and growth mechanism of the different phases during infiltration of a porous ceramic body with liquid silicon. The main goals of the investigations are to improve the mechanical properties of the composites by reducing the fraction of the residual silicon and to develop an environmentally friendly fabrication process. The activity requires in-depth thermodynamic analysis of the system, understanding the the high temperature wetting behavior of the ceramic in presence of the molten medium, determination of the structural, morphological properties of the composites, their effect on the relevant static and dynamic mechanical an mechanical properties and ultimately on the ballistic efficiency.
Latest publications
S. Hayun, A.Weizmann, M. P. Dariel and N.Frage, "The Effect of Particle Size Distribution on the Microstructure and the Mechanical Properties of Boron Carbide-Based Reaction-Bonded Composites. International Journal of Applied Ceramic Technology,
6(4),
(2009) 492-500.
S. Hayun, M.P. Dariel, N. Frage, E. Zaretsky, The high-strain-rate dynamic response of boron carbide-based composites: The effect of microstructure, Acta Materialia,
58
(2010) pp. 1721–1731
Shmuel Hayun, Amir Weizmann, Moshe P. Dariel, Nahum Frage, Microstructural evolution during the infiltration of boron carbide with molten silicon, Journal of the European Ceramic Society,
30
(2010) pp. 1007–1014
S. Aroati, M. Cafri, H. Dilman, M.P. Dariel, N. Frage, Preparation of reaction bonded silicon carbide (RBSC) using boron carbide as an alternative source of carbon, Journal of the European Ceramic Society,
31
(2011) 841–845.
2. Transparent armor is in increasing demand for personnel protection in the form of face shields and visors, windows for ground vehicles, armored cars and lookdown windows for aircraft. The materials must display good broadband transparency, erosion-resistance and have to be inexpensive enough for single-use. The materials must be lightweight and have adequate ballistic performance. The major candidates that fulfill these requirements are: single crystal aluminum oxide (sapphire), aluminum oxynitride (ALON) and magnesium aluminate spinel (MgAl2O4). The last one, namely, spinel, has excellent mechanical properties over a wide transparency in the 0.2 to 6 microns range. It is also attractive on account of its relatively simple synthesis and its cubic structure that allows it to be used as polycrystalline material and manufactured by powder technology techniques. Another advanced transparent ceramic of interest for laser gain host crystals and for IR transparent windows is YAG (Yittria-Alumina Garnet).
One approach to improve the processing of polycrystalline transparent ceramics is to use a relatively the novel densification technique called
Spark Plasma Sintering
(SPS). The SPS technique relies on the simultaneous application of elevated temperature, generated by a high current flow that passes through the compacted powder, and the simultaneous application of axial pressure. The scientific activity of our group is related to optimization of the SPS parameters in order to obtain specimens with adequate transparency and improved mechanical and ballistic properties.
Latest publications
1. N. Frage, S. Cohen, S. Meir, S. Kalabukhov, M.P. Dariel, Spark plasma sintering (SPS) of transparent magnesium-aluminate spinel, J. Mater. Sci. 42 (2007) pp. 3273-3276
2. Shay Meir, Sergei Kalabukhov, Natasha Froumin, Moshe P. Dariel, Nahum Frage, Synthesis and Densification of Transparent Magnesium Aluminate Spinel by SPS Processing,
Journal of the American Ceramic Society
(2009) 92, I-2. pp.358-364.
3. Naum Frage, Sergey Kalabukhov, Nataliya Sverdlov, Vladimir Ezersky, Moshe P. Dariel, Densification of transparent yttrium aluminum garnet (YAG) by SPS processing, Journal of the European Ceramic Society 30 (2010) pp. 3331–3337.