The aim of the present Project is to determine the practically applicable limits for the recent discovery at the Laboratory of High-temperature Synthesis and Technology of Inorganic Compounds of the Institute of Chemical Physics of Armenian National Academy of Sciences (SHS-Laboratory), of a principally new method for synthesis the alloys of refractory metals. In combination with the known method of Self-propagating High-temperature Synthesis (SHS), this method, named "hydride cycle" method, can be successfully used for creating the alloys of given new compositions with special physical and chemical characteristics, in particular, of high hydrogen-absorbing ability (applicable as hydrogen storage materials).
These researches will allow us to develop a series of new, pollution-free, high-performance, low power-consuming, high-technology processes for synthesis the binary and multi-component alloys of transition metals and their hydrides, and to recommend their application in different areas of science and technology. The elaboration of such method is an actual problem of modern Material Science. Especially it concerns to the materials with potentially wide application: refractory metal alloys, hydrides of metals and alloys. These materials can be used in high-tech branches of atomic and hydrogen energy, aerospace, chemical industry, machine industry and electronics, medicine (biocompatible alloys), etc.
During prior studies of the SHS processes in Me-H systems, and elaboration of high productive methods for syntheses of hydrides of transition metals, in SHS-Laboratory an idea has arisen, the essence of which consisted in the use of metal hydrides as source materials for synthesis the alloys of the taken metals. Based on this idea, a new method was revealed and named "hydride cycle" method. Using this method, in Ti-Zr;Ti-Hf; Zr-Hf; Ti-Zr-Hf; etc. systems, the alloys had been synthesized, among them – the alloys with structure of ?-, ?-, ?- and ?-phases. The whole process of an alloy synthesis from corresponding hydrides lasted no more than 2 hours. It was shown that the obtained alloys can interact with hydrogen in the SHS mode, forming the alloy hydride with high hydrogen content (Н/Ме ? 2).
The "hydride cycle" (HC) method is an early unknown, high efficient way for producing alloys of refractory metals. It is provided with several essential advantages against traditional methods (induction or arc fusion, powder metallurgy, etc.). The implemented works allowed establishing a new direction of future investigations.
Тhe complex fundamental and applied problems:
a. Researches in fundamental aspects
The detailed study of mechanism of formation of alloys of IIIВ-VIIIВ group and rear-earth metals in HC mode.
The study of the possibility to synthesize the new alloy compositions of refractory metals of IIIB-VIIIB groups with BCC structure, which are promising as hydrogen accumulators and as catalysts, improving sorption properties of metals (Mg, V, etc.). The study of influence of doping with Zr7Ni10; ZrNi; Hf7Ni10 on sorption ability of these alloys.
The detailed study of hydrogen-induced phase transformations in alloys and intermetallics of transition metals, aiming to receive different new modifications with ?-, ?-, ?-, ?-phases and icosahedral quasicrystals (QC).
The study of processes of combustion of new binary and multi-component alloys of different modifications in hydrogen in SHS mode, resulting in synthesis of their hydrides.
The study of possibility of synthesis of intermetallic compounds in MeIV-V-Al systems and their hydrides in HC.
b. Researches in applied aspects
The creation and research of new compositions of binary and multi-component refractory alloys with improved hydrogen binding and dissociation kinetics, aiming to generate promising autonomous energy sources of multiple action, based on Ti-V, Ti-V-Mn, Ti-Nb, etc. The creation of alloys with high hydrogen-binding ability (hydrogen storage materials) in Ti-V-Cr system; investigation of their absorption-desorption characteristics at doping with Zr7Ni10; ZrNi; Hf7Ni10. Quest of new composition multi-component hydrides, perspective as hydrogen storage.
Determination of optimum parameters of synthesis of alloys and their hydrides with the brightest hydrogen absorption-desorption characteristics. Research of influence of hydrogen content, chemical composition, crystalline structure and size of powder particles in the source hydrides (micro- and nano-scale), and conditions of dehydrogenation-sintering on physical, chemical and mechanical properties of synthesized alloys and their hydrides.
Synthesis of Ti-V-Nb-Al; Ti-Al; Nb-Al; etc. based alloys, suitable as biocompatible materials (implantants).
Synthesis in HC of pseudo-alloys in Cu-Nb and Cu-V systems, having ultrahigh strength and electrical conductivity (within 65-75% of the conductivity of pure copper) and effective as electrical engineering materials.
c. Development of technology
During implementation of this Project the following technologies will be developed:
the high-productive HC technological processes for synthesis of binary and multi-component alloys of refractory metals with non-trivial structure and high exploitation features (heat-, wear- and corrosion-resistant, solid, with high electrical conductivity, superconductivity and effective absorption-desorption characteristics) ;
the ecologically clean SHS technological process for synthesis of hydrides, which can be recommended as source materials at formation of alloys in HC mode; as well as for synthesis the hydrides of these alloys, as potential hydrogen storage materials.
d. The demonstration of technology
The technological processes, designed in the Laboratory conditions, can be demonstrated at the Institute of IChPh ANAS. The real bases for fulfillment of the present Project are the background developments on syntheses of hydrides in SHS mode, previously carried out at the IChPh of Arm. NAS for more than 30 years.
The strong foundations for successful carrying-out the suggested new complex studies are: a) the experience and knowledge of the research personnel at IChPh of ANAS in the field of Material Science of hydrides, Metal Science of alloys of refractory metals, chemical physics and solid state physics; b) the available at the Institute instruments, materials and equipment, in particular, SHS technique for synthesis of initial binary hydrides of transition metals.
We expect that at completion of this Project, the following results will be obtained: The technological processes of synthesis in HC of most perspective alloys of transition metals and their hydrides with outstanding characteristics will be developed; a new series of concrete, practically important compositions of multi-component alloys, and of new structures of doped alloys of transition metals and their hydrides with maximum concentration of hydrogen will be created.
The economic aspects: The new technologies designed in HC mode will present the commercial interest due to of a number advantages over the traditional technologies, such as: reduced work temperature (600-1200оС instead of 1800-2600оС); shorter duration of processing for formation of refractory metal alloys (1.5-2 hours instead of dozens hours); mono-stage, waste-less technique without multiple re-melting; availability of high-performance technological SHS process of syntheses of source hydrides of transition metals required for synthesis the alloys in HC; etc. The perspectives of application of new technology will be very attractive for industry due to its cheapness. The creation of multi-component alloys of transition metals and hydrogen-rich hydrides of alloys with specific features can greatly increase the areas of their application.
The scientific team of IChPh of Armenian NAS for many years worked on development of the technologies for producing new materials, demanded in the defense entities (for example, at the Kurchatov Institute of Nuclear Energy, P.O. Boxes 7210, A-1928, B-2652). The funding of this Project will give this team a chance to re-orient their scientific interests and to direct their activity into peace. It will also assist the integration of Armenian scientists into international community and participation in decision of the international scientific problems in the field of Material Science of alloys and their hydrides, as well as of environment.
In 1998-2001, together with the researchers from the Yerevan Physics Institute (YerPhI), the scientists of SHS Laboratory worked on ISTC Project # A-192 "The influence of electron beam on the formation of binary and multi-component hydrides with extreme properties". During the implementation of this Project, the thermal-radiation synthesis of hydrides of transition metals was realized for the first time, the hydrogen-rich hydrides of stoichiometric compositions were obtained; the super-hydride of hafnium (HfH2.4) was synthesized for the first time. The new phenomenon of "cold synthesis" of hydrides, carbohydrides, hydridonitrides and hydrides of intermetallics has been revealed.
In 2006-2008, again with the researchers from YerPhI, the team worked on, and successfully completed ISTC Project # A -1249 titled: “Self Propagating High Temperature Synthesis of Hydrides with Maximum High Content of Hydrogen”. During performing this Project, a fundamentally new, efficient method of generating the alloys and intermetallics of refractory metals has been demonstrated, based on usage as source materials the hydrides of these metals. It was shown, that the combustion of obtained compounds in hydrogen in SHS mode resulted in synthesis of their hydrides. On the neutron diffractometer E3, on NRU reactor, Chalk-River (foreign collaborator Dr. John H. Root, Ontario, Canada) the neutron shielding characteristics of synthesized metal hydrides were studied; neutronographic and x-ray study of 42, synthesized samples, transferred to Canada, was performed. The collaborator of the Project, Dr. Prof. Jacques Huot at the Institut de recherche sur l’hydrogene, Universite du Quebec a Trois-Rivieres, studied BCC alloys, based on Ti0.6V0.4 and Ti0.7V0.3, and of their hydrides, as catalysts under hydrogenation of Mg and its alloys.
The Project #A-1794 "The using of SHS and "hydride cycle" techniques for receiving alloys of transition metals with high hydrogen adsorbing properties, as effective hydrogen storage", has been submitted to the ISTC in October 2009. It was adopted by the Technical Commission of ISTC and approved by the Financing Parties. Moreover, Canada was going to start funding, but because of limited funds of ISTC, our Project received status 3: «Approved without funding».
2009-2011 - IAEA Research Contract number 15720, 'The Receiving of Alloys of Transition Metals with High Hydrogen Absorbing Properties Using SHS and "Hydride Cycle" Techniques and Application of Nuclear Methods for their Microstructural Characterization’.
