Nanostructure Microspherical Powders
Tech Area / Field
- MAT-ALL/High Performance Metals and Alloys/Materials
- CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
- CHE-SYN/Basic and Synthetic Chemistry/Chemistry
- MAT-SYN/Materials Synthesis and Processing/Materials
3 Approved without Funding
Baykov Metallurgy and Materials Institute, Russia, Moscow
- NIKIMT (Institute of Assembly Technology), Russia, Moscow
- Universidade da Coruña / Escola Politécnica Superior, Spain, Ferrol\nForschungszentrum Karlsruhe GmbH / Institute of Nanotechnology, Germany, Karlsruhe\nLos Alamos National Laboratory, USA, NM, Los-Alamos\nUniversität Stuttgart / Institute for Manufacturing Technologies of Ceramic Components, Germany, Stuttgart\nUniversity of New Orleans, USA, LA, New Orleans
Project summaryThe Project’s goals are to study physical-chemical properties in local volume by pyrolise of cation-containing sprays in gas flows, and basing on obtained data to develop technique of synthesis of several-purposed nano-structured micro-spheric powders, which ensure high technological properties by further manufacture of final products.
The Project's main matter. At present time there is a growing interest over the world in nano-crystalline and nano-amorphic materials, and in their practical applicability in high-technological industrial areas. Such attention to the new-age materials is because of great prospects due to their unique physical-mechanical characteristics and to high activity grade by caking process with forming of ultra-disperse structure. Growing interest of material researchers is firstly in nano-scaled powder materials. In this case, in order to achieve extremum material properties, developers try to obtain maximum dispersed powders. However, such increase of powders' disperse leads by following treatment to significant technological problems. At first, due to great specific surface of nano-scaled powders, there is forming of multi-particle agglomerate from separate nano-particles. Because of this, there is very expressed local irregularity of particles compactness, which leads to negative results by caking and to degradation of physical-mechanical properties of products. The high dispersed powders obtained by more traditional technology of crystallization from solution (deposition method), are featured by initial phase of caking of contacting of nano-scaled particles. It also leads to forming of very irregular agglomerated structure, which can be hardly destroyed by the known methods of fragmentation and dispersing.
At present time there is a number of technologies developed for obtaining of high-dispersed powders. In particular, special methods of wet chemical technology or gas-phase condensing methods (plasma-chemical synthesis, CVD-process) are applicable for production of transformation-reinforced ceramics on base of zirconium dioxide, silicon carbide or silicon nitride. Dimensions of particles in these powders are hundredths of micrometer. However, such high-dispersed powders are not widely applicable in practice because of it is necessary to use special expensive technological forming methods (hot or cold iso-static compressing, schliecker casting process with organic fillers, etc.), in order to ensure high quality of nano-powder products. These methods often give no intended effect and cause a lot of restrictions, which lay obstacles to mass-production.
With use of methods allowing to obtain nano-powders with particles os proper spherical form and small dimensional deviation, it is possible to avoid these negative phenomena. One of such methods is a spray-method of nano-structured powder obtaining. However, the productivity of this process is very low: about 0.5 g per month. The Laboratory experiments performed in Russia showed, that synthesis of nano-structured powders basing on cation-containing sprays pyrolise in combination with wave generation of spray particles, allows to increase by tens times productivity of this process, ensuring its commercial availability.
The scientific value of the Project is in pioneer research of the unique process of disbalansed crystallization in local micro-volumes, with obtaining of nano-powder raw material with internal nano-scaled structure. In contrast to ultra-dispersed powders with insulated nano-particles, such powders save all advantages of the nano-scaled powders due to their high activity by forming of compact material, and have un doubt prospects in modern materials technology by application of traditional forming technologies.
The Project’s results shall be:
a) design and manufacture an universal research for stand for study of cation-containing sprays pyrolise in gas flows;
b) experimental study of obtaining of actual nano-structured micro-spherical metal- and non-metallic powders;
c) comprehensive analysis of properties of obtained nano-structured micro-spherical powder materials, physical-mechanical tests of some products made of them;
d) basing on research results, development of means of production of actual types of nano-structured micro-spherical powders (SiC, Si3N4, Al2O3 and Ta).
The means of production of concrete types of nano-structured micro-spherical powders shall ensure further development and manufacture universal high-productive equipment for industrial production of several purposed nano-structural micro-spherical powders.
The spray nano-structured powders should be competitive in the powder raw materials market. They allow to produce new structural and functional materials, which excel available analogues by strength, cracking-resistance and others physical-mechanical characteristics, due to their super-fine structure of caked poly-crystalline material. A low caking temperature for these powders ensures significant decrease of power consumption by industrial production. Cost price of produced parts should be quite low because of excluding of some treatment operation for the sprayed powders (milling and fragmentation, qualification, purification from admixtures, etc.), and because of application of cheap traditional technologies for processes of forming and caking.
The high-pure aluminum oxide is wide applicable for manufacture of orthopedic hip-implantants and their spherical friction pairs. Application of the developed methods for its production shall meet all demand of Russian medicine in such beside that, produced by mean of the new method nano-structured micro-spherical powders of SiC and Si3N4 could find a wide application in oil and oil-processing industries by production of wear-stable anti-friction packing rings for centrifugal and submerged pumps.