Surface Modification of Materials by Plasma
Surface Modification of Materials by Concentrated Flows of Thermal Heterogeneous Plasma
Tech Area / Field
- PHY-PLS/Plasma Physics/Physics
3 Approved without Funding
Joint Institute for High Temperatures RAS / Institute of High Enegry Densities, Russia, Moscow
- National Academy of Sciences of the Republic of Belarus / Institute of Molecular and Atomic Physics, Belarus, Minsk
- Mississippi University / Cook's Advanced Energy Conversion, USA, MS, Starkville\nEindhoven University of Technology, The Netherlands, Eindhoven\nCNRS / Centre de Physique des Plasmas et de leurs Applications de Toulouse, France, Toulouse\nMississippi University / Center for Advanced Energy Conversion, USA, MS, Starkville\nMississippi University / Diagnostic Instrumentation and Anaysis Laboratory, USA, MS, Starkville
Project summaryThe urgency and objectives of the Project. This project is aimed at solving a number of applied problems associated with the application of high-temperature heterogeneous plasma flows for the synthesis, reprocessing, and surface treatment of materials, and with the monitoring of such technological processes and their environmental safety. In modern plasma devices employed in the treatment of materials, the temperature T of the working medium significantly exceeds 2000 K. The presence of macroparticles in plasma is a basis of the technological process (plasma spraying, processing of disperse materials and waste recycling). The macroparticles in the plasma acquire an electric charge, which may result both in the formation of concentrated flows of macroparticles due to their mutual attraction and in dispersal of macroparticles in space due to their mutual electrostatic repulsion. It is suggested to utilize these properties of dust plasma to develop efficient technologies for the processing and surface modification of materials. Up to date the dust plasma was studied only at T < 2000 K. The part played by macroparticles in high-temperature plasma processes was in fact ignored because of the absence of adequate techniques for the diagnostics of heterogeneous plasma.
Thus, the objective of this project is to study the formation conditions of ordered structures from macroparticles (from 10 nm to 10 mkm in size) in heterogeneous thermal plasma at T > 2000 K; the realization of these conditions for the development and demonstration of advanced technologies for deposition of coatings with metallurgical bond on parts of machines and mechanisms, as well as for the processing of dispersed materials; and the development of plasma stand for commercial realization of the technological processes identified above.
Information about the participants of the Project. Teams from two institutes will take part in the Project: the Leading Institution - Institute for High Energy Densities of the Associated Institute for High Temperature of Russian Academy of Sciences (IHED AIHT RAS) and the Participant Institution - the Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus (IMAPh NASB). All in all, 45 persons are involved, among them 20 persons are "weapons" specialists. The "weapons" specialists have extensive experience working in the military field: diagnostics of media subjected to the effect of nuclear blast, the development of rocket engines and systems of rocket refueling, the development of heat shielding of ballistic rockets, and the diagnostics and optimization of the active media of powerful lasers for military applications. The teams include eight doctors of sciences and fourteen candidates of sciences. During the last five years, the participants of the Project published well over 20 papers on the subjects related to the Project, including 13 publications in journals subjected to reviewing.
Expected results and their application. The Project falls under the category of "Applied Investigations and Development of a Technology". The following four major problems must be solved for the execution of the Project:
- Development of diagnostic methods and equipment for determining the parameters of heterogeneous plasma at Т > 2000 К;
- Development of an experimental complex for heterogeneous thermal plasma generation with preassigned reproducible parameters at Т > 2000 К to study the interaction of macroparticles with plasma and solid surface;
- Diagnostics of a heterogeneous thermal plasma for the purpose of optimizing high-temperature technological plasma processes of plasma treatment of materials; and
- Development of the fundamentals of the technology for treating materials by concentrated flows of heterogeneous plasma, and the preparation and testing of experimental prototype of plasmatron.
The solution of the foregoing four problems of the Project will result in:
- the development of diagnostic methods and equipment for determining of heterogeneous plasma parameters at T > 2000 K;
- experimental complex for generation of a heterogeneous thermal plasma with preassigned reproducible parameters for studying of the macroparticles behavior in plasma and the investigation of the interaction between thesemacroparticles and solid materials, as well as for development of the fundamentals of the technology for treating materials by concentrated flows of heterogeneous thermal plasma;
- the determination of the particle parameters in a heterogeneous thermal plasma and of the optimal plasma parameters for the metallurgical coating deposition technology and processing of dispersed materials;
- the development of resource-saving plasma technology for spraying the powdery materials on metals to form the protective coatings with metallurgical bond on parts of machines and mechanisms; the development type of plasmatron will be manufactured, and industrially tested for these technologies application; the plasmatrons and the diagnostic equipment for monitoring the heterogeneous plasma parameters will make up a complete requisite set of process equipment of interest to companies engaged in the processing and surface modification of materials
.It is planned to protect the intellectual property represented by the process equipment developed under the Project.
The effect of the Project on progress in the relevant field of investigations. The completion of the Project will promote the development of the fundamentals of efficient, resource-conserving, environmentally benign plasma technologies for deposition of protective coatings on metals, which properties (adhesion of >150 MPa, and the porosity of <0.5%) significantly exceed those of coatings produced by the conventional methods of plasma spraying and surfacing.
The Project meets the ISTC goals and objective:
- it offers the participants previously dealing with weapons a possibility of reorienting their capabilities toward the development of efficient plasma technologies of surfaces treatment of materials;
- it promotes the integration of researchers from Russia and Belarus into the international scientific community, the establishment of contacts with scientists from Europe and the USA;
- it is aimed at solving basic and applied research problems in the field of surface treatment and synthesis of new materials, designing plasma generators, and developing equipment to control the plasma technologies;
- it promotes the solution of global engineering problems associated with the development of the fundamentals of energy- and resource-conserving plasma technologies which make it possible to reclaim and manufacture working parts of machines and mechanisms by way of deposition of wear-resistant coatings with metallic bond on their surfaces;
The plasma technologies developed under the Project may be introduced at industrial enterprises both in the countries participating in the Project and in other countries, which provides a basis for transition to the market economy answering the civil needs.
The scope of activities. The overall labor input into the Project is estimated at 400 man-months, with the overall labor input by the "weapons" specialists of 235 man-months. Primary activity within the Project is directed to development of diagnostic methods of heterogeneous plasma at temperature above 2000 K, creation of the diagnostic optical-spectroscopic and laser equipment, and determination of optimum heterogeneous plasma parameters for realization of technologies of plasma processing and surface modification of materials. Theoretical and numerical analysis of the part played by basic physical processes in a heterogeneous thermal plasma and the development of a laboratory-scale prototype of the automatic diagnostic complex for determining the parameters of this plasma will be performed by the IHED AIHT RAS team (Task 1). Experiments involving the investigation of heterogeneous thermal plasma will be jointly performed by the IHED AIHT RAS and IMAPh NASB teams using the experimental set-up developed on the base of the high-current arc plasmatron at IMAPh NASB (Task 2). Task 3 will involve the experimental determination of the heterogeneous thermal plasma parameters (size, concentrations, and refractive indices of macroparticles, their charges, velocity spectra and diffusion coefficients; concentrations of the plasma component; the temperature of gas and macroparticles) and the elaboration of the optimal operating conditions for the technological process for coating deposition (to be performed by IHED AIHT RAS and IMAPh NASB). The preparation and industrial testing of experimental prototype of plasmatron, as well as the investigation of the surface zones of materials after being subjected to the effect of plasma (Task 4), will be executed by IMAPh NASB.
The role of foreign collaborators. Foreign collaborators will take part in the discussion of the obtained results; in the preparation and writing of reports on the Project and joint publications of papers and presentations; they will make expert estimates of the activities, equipment, and technologies developed under the Project. It is expected that Prof. G. Kroesen will assist (and take direct part) in establishing contacts with industrial companies in the Netherlands and other countries of the European Community interested in new efficient technologies of surface treatment of materials.
Technical approach and methodology. To date the authors of the Project have performed a number of pioneering investigations related to the subject of the Project. It has been demonstrated that the so-called thermophoretic attraction of macroparticles is possible in a thermal plasma, which promotes the formation of concentrated flows of positively charged macroparticles [A.P. Nefedov, O.F. Petrov, A.A. Samaryan, Ya.K. Khodataev, and S.A. Khrapak, Nauchnye Trudy ITES OIVT, Issue 2 (1999) 213]. The effect of acceleration of charged macroparticles in a low-pressure carbon arc during formation of a coating on the cathode has been discovered [I.P. Smyaglikov and V.D. Shimanovich, J. Eng. Phys. Thermophys. 75, Issue. 4 (2002) 811]. The possibility has been demonstrated to develop carbon coatings for steel, which are characterized by high microhardness and wear-resistance. Formation of dense metallurgical coating has been revealed at spraying of powder materials in plasma of arc column of atmospheric pressure [V.D. Shimanovich, I.P. Smyaglikov, and A.I.Zolotovsky. J. Eng. Phys. Thermophys. 75, Issue 6 (2002) 1256; I.P. Smyaglikov, V.D. Shimanovich, and Y.V. Khodyko. J. Eng. Phys. Thermophys. 76, Issue 1 (2003) 104]. Methods of optical diagnostics of heterogeneous plasma media have been developed [A.A. Samarian, O.S. Vaulina, A.P. Nefedov, O.F. Petrov. Plasma Phys. Reports, 26, №7 (2000) 586; O.S. Vaulina, A.P. Nefedov, O.F. Petrov, and V.E. Fortov, Zh. Eksp. Teor. Fiz., 119 (2001) 1129].
The methodology of the problems solving in the Project is based on the use of optical-and-spectroscopic, laser-absorption, and thermophysical methods for integrated studies of processes of macroparticle interaction with plasma and solid surface; on the determination of the time-spatial structure of the heterogeneous plasma (temperature fields, plasma velocity and density, velocity and size of macroparticles); and on the study of structure and properties of modified surfaces. The plasma generators and automatic means of diagnostics developed by the authors of the Project will be novel and conform to the present-day international standards.