Romnet-Era network

The National Institute of Physics for Lasers, Plasma and Radiation (NIPLPR) Magurele-Bucharest ( Romania) is one of the physics institutes belonging to Institute of Atomic Physics (IFA- Magurele-Bucharest), one major research center in Romania.
The general goal of the NIPLPR is to conduct high level basic and applied research in some selected areas of Lasers, Plasma and Radiation Physics and Applications in the mentioned fields. With a high qualified personnel the NIPLPR is implied an important number of national and international R &D projects.

The group developed an original technology called Thermionic Vacuum Arc (TVA), suitable for nanostructured, multifunctional film preparation as: (i) Diamond like Carbon (DLC) films for MEMS (Micro-Electro-Mechanical-Systems), (ii) Tribological coatings, (iii) Giant magneto-resistive (GMR) films, (iv) High Temperature Resistant to Oxidation films

Abstract regarding the results and scientific and technical potential with respect to chapters 3.4.2. si 3.4.3, FP6 - NMP call

I. The TVA method was developed to grow carbon films for MEMS (Micro-Electro-Mechanical-Systems) applications. Microsystems domain represents a growing interest due multiple applications in health care, environment, automotive and aero-spatial industries, etc. being developed in the frame of many European programs. Even Silicon used in many applications its usage is limited due to the low mechanical and wear resistances as well as the high coefficient of friction between Si and SiO 2. Diamond like carbon ( DLC) is an extremely interesting prospective material for MEMS due to its superior wear-resistant qualities, hydrophobicity, resistance to stiction (i.e. a combination of stickiness and friction) and potential as a biocompatible material. Thermionic vacuum arc method was adopted to prepare DLC films on Si and glass substrates , being identified DLC phase with sp 3 bonds up to of 89% and diamond crystallites size of 3-11 nm. Atomic force and electron transmission microscopes, Raman and X-ray photoelectron spectroscopes, were used to characterize the morphology and the phase composition of the samples after the growth stages.

II. A new class of advanced materials with controlled tribological properties and environmental friendliness is currently developed in order to be applied in the automotive industry as anti-friction layer for plain bearing. Thin film deposition process by TVA, a new discharge type in pure metal vapor plasma, might become one of the most suitable technologies to improve significantly the tribological properties of the surfaces. Due to the continuous electron bombardment of the anode, the main feature of the TVA method, by the accelerated thermo-electrons, its material first melts and afterwards starts to evaporate ensuring a steady state concentration of the evaporated atoms in the cathode-anode space. At further increase in the applied high voltage, a bright discharge is established inside the vacuum vessel in the vapors of the pure anode material. The energy of ions of the TVA plasma can be directly controlled and established at needed value even during arc running by changing the cathode heating current and anode potential, the ion bombardment ensuring higher quality of the deposited thin film.

III. Magnetoresistive films were developed by using TVA method. GMR structure presents the property to change its electrical resistance by 10-60% in the presence of magnetic field, compared to the resistance in the absence of the magnetic field. By using TVA method, the inclusion of gases that minimise the GMR effect is avoided. The film deposition is performed under the ovn metallic ion bombardment having the energy of order of the 100-600 eV. Performing simultaneously discharges in two pure vapors of metals metals (one magnetic and one non-magnetic) were obtained films presenting the GMR effect of 10-30% in only 5 minutes of deposition, overpassing by far other deposition methods.

IV. In order to prepare composite films to be used as components of high temperature oxidation resistant coatings for turbine blades Re-Cr films were prepared in such ratio that can not be obtained by alloying using classical methods. It was developed a system for simultaneous deposition using the same vacuum vessel the two different metals, Re and Cr. Analyzed by SEM the prepared films were compact, uniform and no columnar structured. Thermogravimetric analysis showed that t he mass of the samples was practically constant sustaining the chemical stability assumption in an oxidant atmosphere of the studied composites.

C. P. Lungu, Nanostructure influence on DLC-Ag tribological coatings, Surface and Coatings Technology, In Press, Corrected Proof, Available online 8 April 2005
V. Kuncser, I. Mustata, C. P. Lungu, A. M. Lungu, V. Zaroschi, W. Keune, B. Sahoo, F. Stromberg, M. Walterfang, L. Ion and G. Filoti, Fe–Cu granular thin films with giant magnetoresistance by thermionic vacuum arc method: Preparation and structural characterization, Surface and Coatings Technology, In Press, Corrected Proof, Available online 10 March 2005,
C.P. Lungu, I. Mustata, G. Musa, A.M. Lungu, V. Zaroschi, K. Iwasaki, R. Tanaka, Y. Matsumura, I. Iwanaga, H. Tanaka, T. Oi and K. Fujita , Formation of nanostructured Re–Cr–Ni diffusion barrier coatings on Nb superalloys by TVA method, Surface and Coatings Technology, In Press, Corrected Proof, Available online 12 April 2005
C. P. Lungu, K. Iwasaki, K. Kishi, M. Yamamoto and R.Tanaka, Tribo-ecological coatings prepared by ECR-DC sputtering, Vacuum, 76, Issues 2-3,119-126. 2004
C. P. Lungu, Silver based overlays for tribological applications, Editor BREN, ISBN 973-648-353-3, pp.1-69, 69 pg., 2004.
C. P. Lungu , I. Mustata , G. Musa, V. Zaroschi, Ana Mihaela Lungu and K. Iwasaki: Low friction silver-DLC coatings prepared by thermionic vacuum arc method, Vacuum, 76, Issues 2-3, 127-130, 2004
I. Mustata, C. P. Lungu, A. M. Lungu, V. Zaroski, M. Blideran and V. Ciupina: Giant magnetoersisitve granular layers deposited by TVA method: Vacuum, 76, Issues 2-3, 131-134
O. Fukumasa, K. Osaki, S. Fujimoto, C. P. Lungu , A. M. Lungu, Low friction coatings prepared by plasma electrode spray gun, Surf. and Coating Techn., Vol. 169-170 (2003), pp. 415-418.
C. P. Lungu,Y. Matsumura, M. Yoshinari: Titanium Coating of Scaffold Carbon Foam by ECR Sputtering, Materials Transactions, Vol.43 No.12 (2002) pp.3025-3027.
C. P. Lungu, K. Iwasaki: In-situ monitoring of plasma parameters in the afterglow region of ECR sputtering system for tribological coatings, Vacuum , 66 (2002) 197-202
C. P. Lungu, K. Iwasaki: Influence of surface morphology on the tribological properties of silver-graphite overlays, Vacuum , 66 (2002) 385-39

Network partners and their offer in the NMP field - KNOWLEDGE-BASED MULTIFUNCTIONAL MATERIALS and NEW PRODUCTION PROCESSES AND DEVICES

	National Institute for Lasers, Plasma and Radiation Physics Name of the Network: Multifunctional materials Organisation name: National Institute for Lasers, Plasma and Radiation Physics Contact person, scientific title: Dr. Cristian P. Lungu Department: Elementary Processes in Plasma and Applications Group Organisation’s address: 409 Atomistilor, POBox MG-36, Magurele- Bucharest Post code 755127 City: Bucharest Country: Romania Organisation type: National Institute (R&D) Organisation size: 300-400 employees Web site: www.inflpr.ro E-mail address: [email protected], [email protected] Telephone: 0040214574550/1658 Fax: 0040214574468 Brief description of the organization The National Institute of Physics for Lasers, Plasma and Radiation (NIPLPR) Magurele-Bucharest ( Romania) is one of the physics institutes belonging to Institute of Atomic Physics (IFA- Magurele-Bucharest), one major research center in Romania. The general goal of the NIPLPR is to conduct high level basic and applied research in some selected areas of Lasers, Plasma and Radiation Physics and Applications in the mentioned fields. With a high qualified personnel the NIPLPR is implied an important number of national and international R &D projects. Brief description of involved Department The group developed an original technology called Thermionic Vacuum Arc (TVA), suitable for nanostructured, multifunctional film preparation as: (i) Diamond like Carbon (DLC) films for MEMS (Micro-Electro-Mechanical-Systems), (ii) Tribological coatings, (iii) Giant magneto-resistive (GMR) films, (iv) High Temperature Resistant to Oxidation films Abstract regarding the results and scientific and technical potential with respect to chapters 3.4.2. si 3.4.3, FP6 - NMP call I. The TVA method was developed to grow carbon films for MEMS (Micro-Electro-Mechanical-Systems) applications. Microsystems domain represents a growing interest due multiple applications in health care, environment, automotive and aero-spatial industries, etc. being developed in the frame of many European programs. Even Silicon used in many applications its usage is limited due to the low mechanical and wear resistances as well as the high coefficient of friction between Si and SiO 2. Diamond like carbon ( DLC) is an extremely interesting prospective material for MEMS due to its superior wear-resistant qualities, hydrophobicity, resistance to stiction (i.e. a combination of stickiness and friction) and potential as a biocompatible material. Thermionic vacuum arc method was adopted to prepare DLC films on Si and glass substrates , being identified DLC phase with sp 3 bonds up to of 89% and diamond crystallites size of 3-11 nm. Atomic force and electron transmission microscopes, Raman and X-ray photoelectron spectroscopes, were used to characterize the morphology and the phase composition of the samples after the growth stages. II. A new class of advanced materials with controlled tribological properties and environmental friendliness is currently developed in order to be applied in the automotive industry as anti-friction layer for plain bearing. Thin film deposition process by TVA, a new discharge type in pure metal vapor plasma, might become one of the most suitable technologies to improve significantly the tribological properties of the surfaces. Due to the continuous electron bombardment of the anode, the main feature of the TVA method, by the accelerated thermo-electrons, its material first melts and afterwards starts to evaporate ensuring a steady state concentration of the evaporated atoms in the cathode-anode space. At further increase in the applied high voltage, a bright discharge is established inside the vacuum vessel in the vapors of the pure anode material. The energy of ions of the TVA plasma can be directly controlled and established at needed value even during arc running by changing the cathode heating current and anode potential, the ion bombardment ensuring higher quality of the deposited thin film. III. Magnetoresistive films were developed by using TVA method. GMR structure presents the property to change its electrical resistance by 10-60% in the presence of magnetic field, compared to the resistance in the absence of the magnetic field. By using TVA method, the inclusion of gases that minimise the GMR effect is avoided. The film deposition is performed under the ovn metallic ion bombardment having the energy of order of the 100-600 eV. Performing simultaneously discharges in two pure vapors of metals metals (one magnetic and one non-magnetic) were obtained films presenting the GMR effect of 10-30% in only 5 minutes of deposition, overpassing by far other deposition methods. IV. In order to prepare composite films to be used as components of high temperature oxidation resistant coatings for turbine blades Re-Cr films were prepared in such ratio that can not be obtained by alloying using classical methods. It was developed a system for simultaneous deposition using the same vacuum vessel the two different metals, Re and Cr. Analyzed by SEM the prepared films were compact, uniform and no columnar structured. Thermogravimetric analysis showed that t he mass of the samples was practically constant sustaining the chemical stability assumption in an oxidant atmosphere of the studied composites. Selected references: C. P. Lungu, Nanostructure influence on DLC-Ag tribological coatings, Surface and Coatings Technology, In Press, Corrected Proof, Available online 8 April 2005 V. Kuncser, I. Mustata, C. P. Lungu, A. M. Lungu, V. Zaroschi, W. Keune, B. Sahoo, F. Stromberg, M. Walterfang, L. Ion and G. Filoti, Fe–Cu granular thin films with giant magnetoresistance by thermionic vacuum arc method: Preparation and structural characterization, Surface and Coatings Technology, In Press, Corrected Proof, Available online 10 March 2005, C.P. Lungu, I. Mustata, G. Musa, A.M. Lungu, V. Zaroschi, K. Iwasaki, R. Tanaka, Y. Matsumura, I. Iwanaga, H. Tanaka, T. Oi and K. Fujita , Formation of nanostructured Re–Cr–Ni diffusion barrier coatings on Nb superalloys by TVA method, Surface and Coatings Technology, In Press, Corrected Proof, Available online 12 April 2005 C. P. Lungu, K. Iwasaki, K. Kishi, M. Yamamoto and R.Tanaka, Tribo-ecological coatings prepared by ECR-DC sputtering, Vacuum, 76, Issues 2-3,119-126. 2004 C. P. Lungu, Silver based overlays for tribological applications, Editor BREN, ISBN 973-648-353-3, pp.1-69, 69 pg., 2004. C. P. Lungu , I. Mustata , G. Musa, V. Zaroschi, Ana Mihaela Lungu and K. Iwasaki: Low friction silver-DLC coatings prepared by thermionic vacuum arc method, Vacuum, 76, Issues 2-3, 127-130, 2004 I. Mustata, C. P. Lungu, A. M. Lungu, V. Zaroski, M. Blideran and V. Ciupina: Giant magnetoersisitve granular layers deposited by TVA method: Vacuum, 76, Issues 2-3, 131-134 O. Fukumasa, K. Osaki, S. Fujimoto, C. P. Lungu , A. M. Lungu, Low friction coatings prepared by plasma electrode spray gun, Surf. and Coating Techn., Vol. 169-170 (2003), pp. 415-418. C. P. Lungu,Y. Matsumura, M. Yoshinari: Titanium Coating of Scaffold Carbon Foam by ECR Sputtering, Materials Transactions, Vol.43 No.12 (2002) pp.3025-3027. C. P. Lungu, K. Iwasaki: In-situ monitoring of plasma parameters in the afterglow region of ECR sputtering system for tribological coatings, Vacuum , 66 (2002) 197-202 C. P. Lungu, K. Iwasaki: Influence of surface morphology on the tribological properties of silver-graphite overlays, Vacuum , 66 (2002) 385-39