History of the Institute

1. INSTITUTE OF GENERAL AND INORGANIC CHEMISTRY OF THE NATIONAL ACADEMY OF SCIENCES OF THE REPUBLIC OF ARMENIAIGIC NAS RASpeaker: Dr. Torosyan 2-tup., Argutyan street 10, 375051, Yerevan, R APhone: (3741) 23-07-38, facsimile (3741) 23-12-75E-mail: atorosyan @ netsys. am

2. History of the Institute • IGIC NAS RA was founded in 1957. The basic themes of Institute’s activity in the period 1957 -2000 were: • Complex processing of rocks for various productions. Particularly the rocks of nephelin cianits, naturale criolits, bentonits and perlits were investigated. • Complex processing of industrial waste such as F-containing waste materials and phospho-gypses. • Synthesis of superhard materials and new method of metallic and composite coatings. • The complex processing of low gold-containing rocks.

3. Current Activities of the Institute • Laboratory of Solid State Chemistry. Synthesis of Super hard Materials. Metallic and composite coatings. Head of Lab. Dr. Torosyan • Laboratory of Adsorbents. High Quality Bentonite Adsorbents and Vollastonit . Head of Lab.Dr.G. Martirosyan • Laboratory of Ceramic Paints. New Ceramic Paints for Anticorrosion Protection. Head of Lab. V. Ovchiyan • Laboratory of Corundum. Production of Ultra Disperse Corundum Ceramics. Head of Lab. A.Khanamirova

4. METHOD FOR SYNTHESIS OF SUPERHARD MATERIALS • The aim of the present method is to offer a new technology for synthesis of superhard materials such as diamond and boron nitride micro-powders, spherical mono-crystalline corundum and silicone carbides, etc. by using high pressure and temperature generated during mechanically induced detonation of solid phase exothermal systems. • The method is based on behaviour analysis of solid phase systems under mechanical perturbation conditions.

5. Accumulation of Mechanical Energy in Some Solid Phase Systems Such As [MeO-Me1] [MeS- Me1]and Transition of the Systems to Detonation while Burning Slowly 1 dQ/dT(a.u) E Activated state Initial state 2 E2 Activated state 1 2 Initial state E1 3 products 0 200 400 600 800 ToC Reaction axis Fig.1 Accumulation of Mechanical Energy in CuO-Al System Fig.2 The scheme of energy accumulation

6. The Principle of the Method Suggested • Thus, the distinctive feature of the proposed method is that in normal conditions the interaction between components in the considered systems takes place in a slow-burning regime while the front of the reaction here is the relaxation area. After the mechanical activation, the same reaction mixtures interact with detonation. • Speed of Detonation is 1.5-3 km/s • Pressure is 50-150 HPa • Temperature is 2000-3000oC

7. Micrographs of the particle size transformation and distribution Graphite particle partially transferred to diamond. X 1000 The mixture of Graphite and diamond transferred particles X 500

8. CONCLUSIONS • It has to be noted that the proposed method is economically viable and can be obtained in fool-proof manner. • Diamond being coated by corundum exhibit a high temperature stability. • The main obstacle encountered is the chemical purification of the after-explosion-mixtures described.

9. Application of Technologies For Super Hard Materials List of Suggested Industry Sectors • Stone and glass production:surface treatment and polishing of hard materials, stones, ceramics, glasses • Jewellery production: diamond crystals’, sapphires’, ruby's treatment etc. • Metallurgy: polishing of metal surface • Car industry for polishing of various details • Diamond tools production

10. Metallic and Composite Coatings -Introduction and Overview It is well known that mechanical energy can initiate solid phase interactions. Activation and rate increase of the physical and chemical processes are observed. A new approach was elaborated in this field of mechano-chemistry – metal finishing under the impact of mechanical pulse perturbation. During our experimentation, there were established two principally different ways of metal surface finishing under the same conditions of mechanical treatment : • Direct deformation coating method • Coating formation from oxides’ reduction

11. TWO WAYS OF COATING FORMATION • Metal and composite coatings obtained from the initial simple powder are formed directly. For the Cr coating, Cr powder was used only, while for Al/Si coating pure Al and pure Si powders was used. The mechanism of coating formation is offered based on the theory of solids’ deformation and dislocation theory. Coating-specimen bonding strength is of cold-welding nature, as was shown by our experiments. • The coating is formed when initial oxide compounds containing to-be-coated-metals are reduced under the impact of mechanical perturbation. For example: the Fe-C-H2-Cr2O3 system is used for Cr coating on the steel, while Al-H2-SiO2 isused for S-coating on the Al.

12. THE TYPES OF THE COATINGS OBTAINED • metallic coatings based on the pure metals (Al, Cr, Cu, W Ni, Ti) and alloys (Ti-Cu, Al-Cr, Ti-Al, Ni-Ti, Ni-Al etc.); • Si and C modified surfaces of low-carbon-content steel; • Composite coatings, e.g. so-called metal-armoured fillers, as Co-WC, Al-Al2O3 etc. • Solid-state lubricator superficial films obtained via solid phase synthesis, e.g. MoS2.

13. STRUCTURE AND THICKNESS OF THE COATINGS OBTAINED The thickness of obtained coatings is within the 5 to 100 km range. 60  km Fig.1 Cross section of steel 40x with Cr coating, x 63 Fig.2 cross section of the etched Cr-coating, x 300 Delineated nature of the interstitial layer indicates that no diffusion happened between the substrate and the coating in concern.

14. MECHANICAL PROPERTY OF COATINGS  kg/mm2. Presence of the coating significantly changes the mechanical properties of the of specimen, as it follows from Fig. 3. Particularly, the durability and yield stress increases upon the presence of the coating which is important from the practical point of view. 1y b) 50 0y a) 1e 25 0e 3 5 7 % 1 0 Fig.3. Deformational diagram of Steel a) specimen without coating b) specimen with Cr coating.

15. CONCLUSIONS • It had to be stressed that the full picture of undergoing processes when the coatings were formed is not fully described yet for the lack of proper instrumentation. So, through our collaborative activities we expect to: 1. Elucidate the mechanisms of interaction between the substrate and the material to be coated. 2. Development and optimisation of the technology to obtain composition coatings, solid -lubricant films on metals and alloys. 3. Method design for production.