STAGE 4th 2021


In the final stage of the project, it was established the methodology to check the quality of the thermal barrier coatings based on ZrO2 doped with mixed rare earth oxides from monazite concentrates.

The results obtained for 2 coating samples are presented below:







Coatings based on ZrO2 doped with 8% rare earth mixtures have the appropriate mechanical, adhesion and oxidation cycle resistance characteristics for potential use as thermal barrier applications for gas turbines. Starting from the market study for thermal barriers, carried out for the period 2016-2027, two development solutions of the co-financing company were analysed. The variant that proposes that the company obtains a market share of 5% of the value of the required TB coatings with applications in the field of gas turbines allows the recovery of the investment and a positive cash flow from year 4 after commissioning.


      Dissemination of the project results


  1. Grilli M.L., Valerini D., Slobozeanu A.E., Postolnyi B.O., Balos S., Rizzo A., Piticescu R-R., Critical Raw Materials Saving by Protective Coatings under Extreme Conditions: A Review of Last Trends in Alloys and Coatings for Aerospace Engine Applications, Materials 2021, 14, 1656. https://doi.org/10.3390/ma14071656

  2. Piticescu R-R., Prakasam M., Jay O., Slobozeanu A.E., Burada M., Innovative ideas in the design, re-use and re-fabrication of Rare Earth-based materials in the Context of Microelectronics and Renewable Energy, IEEE-Proceedings CAS 2021

  3. Slobozeanu A.E., Piticescu R-R., Grilli M.L., Valerini D., Prakasam M., Largeteau A., Sobetkii A., “Design, Synthesis and Characterization of Zirconia Ceramics doped with Mixed Rare Earth Oxides”, EMRS Spring Meeting, Symp. S, 03.06.2021/oral, on-line

  4. Piticescu R-R, “Novel thermal barrier coatings based on ZrO2 doped with mixed REOs”, COST CIG ITHACA Industrial Workshop, Raw Materials Week, September 2021, Athens, oral presentation

  5. Ghita A., Irimescu R., Ghita M, Slobozeanu A.E., Grilli M.L., Valerini D., Piticescu R-R, Sobetkii A., „Design, Synthesis and Characterization of Zirconia Ceramics doped with Mixed Rare Earth Oxides”, Raw Materials Week, September 2021, Athens / Virtual Poster6

  6. A.E.Slobozeanu, S.N.Valsan, C.F.Ciobota, M.L.Grilli, M.Prakasam, A.Largeteau, D.Valerini, A.Rinaldi, A.Sobetkii, R.R.Piticescu, MONAMIX - Nou concept pentru extractia eficienta a oxizilor de pamanturi rare din concentrate de monazite si potentialul lor de utilizare in acoperiri pentru temperaturi ridicate si materiale sinterizate, Salonul International de Inventii si Inovatii Traian Vuia, Timisoara, 14.10.2021, medalie de aur

Filmul de promovare al proiectului MONAMIX



SUMMARY RESULTS 2020

      New ZrO2 powders doped with 8% synthetic REOs mixture (containing La, Gd, Y, Nd, Gd, and Yb with a ratio corresponding to natural occurrence in selected La-rich monazite concentrates) have been prepared by a hydrothermal method at moderate temperatures (max. 250 °C) and pressures (max. 40 atm.).

      The XRD pattern of this powder corresponds to a monophasic tetragonal ZrO2 solid solution, consisting of granular aggregates with dimensions up to tens of microns. EDS analysis confirms the presence of REOs doping elements uniformly distributed in the aggregates.

      Coatings architectures deposited on Nimonic 80 A substrates by EB-PVD process were further obtained using these powders, consisting of: NiCrAlY bonding layer (556 nm thickness), ZrO2-8%REOs (1.98 µm thickness), LZO (4.25 µm thickness) and GZO (4.62 µm thickness).

      The results of thermal shock tests show a satisfactory behavior for a number of minimum 150 cycles in the temperature ranges 1200−1300°C for the proposed coating architecture with a total thickness around 11.5 µm. The results are comparable with those of traditional YSZ coatings with thickness > 100 µm, showing the ability of the new coating materials to further improve the thermal properties of TBCs for aeronautical applications..

      Dissemination of the project results


      ISI Publication


  1. “Design, Fabrication, and Characterization of New Materials Based on Zirconia Doped with Mixed Rare Earth Oxides: Review and First Experimental Results”
  2. Authors: Adrian Mihail Motoc, Sorina Valsan, Anca Elena Slobozeanu, Mircea Corban, Daniele Valerini, Mythili Prakasam, Mihail Botan, Valentin Dragut, Bogdan St. Vasile, Adrian Vasile Surdu, Roxana Trusca, Maria Luisa Grilli, Robert Radu Piticescu

    MDPI - Metals 2020, 10, 746; doi:10.3390/met10060746


  3. “Nanostructured Cobalt Doped Barium StrontiumTitanate Thin Films with Potential in CO2 Detection”
  4. Authors: Cristina F. Ciobota, Roxana M. Piticescu, Ciprian Neagoe, Ioan A. Tudor, Alexandru Matei, Dumitru V. Dragut, Arcadie Sobetkii, Elena M. Anghel, Adelina Stanoiu, Cristian E. Simion, Ovidiu G. Florea, Simona E. Bejan .
    Materials 2020, 13, 4797; doi:10.3390/ma13214797

      Book


Book chapter: Synthesis of nanostructured mixed rare earth oxides and their use in designing of sintered zirconia ceramics
Authors: Cristina F. CIOBOTA, Sorina Nicoleta VALSAN, Valentin DARGUT, Anca Elena SLOBOZEANU, Mythili PRAKASAM, Alain LARGETEAU, Felix BALIMA, Maria Luisa GRILLI, Radu Robert PITICESCU
Published in Nanomaterials: Functional Properties and Applications, vol. 28, pg.203-215 Editura Academiei Romane 2020 ISBN 978-973-27-3290-8


      2020 Virtual Conferences: oral presentations


  1. “Ultra-high temperature oxide ceramics for aerospace industry: synthesis, coatings application and impact on energy efficiency”
  2. Authors: R.R. Piticescu, M.L.Grilli, D. Valerini, A. Motoc, M. Botan, V. Manoliu
    10th EASN Virtual International Conference on Innovation in Aviation & Space to the Satisfaction of the European Citizens, 02.09.2020

  3. “Rare earth doped zirconia nanomaterials: synthesis, processing and applications”
  4. Authors: A. E. Slobozeanu, A. M. Mocioiu, D.V. Dragut, R. M. Piticescu, M. L. Cursaru, R.R. Piticescu, B. St. Vasile, A.V. Surdu, M. Prakasam
    Conferinta de Chimie SICHEM 17-18 Septembrie 2020

  5. “Thermal Barrier Coatings based on Rare Earths doped Zirconia Materials obtained by EB-PVD process and their thermal shock properties”
  6. Authors: - A.E. Slobozeanu, S.N. Valsan, M. Corban, R.R. Piticescu, M. Botan, V. Manoliu, B. St. Vasile.
    International Conference of Aerospace Sciences, “AEROSPATIAL 2020”, 15 – 16 October 2020

  7. “Advanced materials for extreme conditions and their impact on space and security applications”
  8. Authors: R.R. Piticescu, A.E. Slobozeanu, S.N. Valsan, M. Corban.
    3rd Conference on Emerging Technologies in Materials Engineering EmergeMAT, 29 October 2020




2nd PHASE (January - December 2019)


Results







      Dissemination of the project results


      Publication


Book chapter: Nanostructured pure and doped Zirconia – Syntheses and Sintering for SOFC and optical applications
Authors: Mythili Prakasam, Sorina Valsan, Yiying Lu, Felix Balima, Wenzhong Lu, Radu Piticescu, Alain Largeteau
Published in Sintering Technology: Method and Application, ISBN 978-953-51-6802-7 INTECHOPEN for open access, http://dx.doi.org/10.5772/intechopen.81323

      Participation in international conferences


  1. “MONAMIX: New Concepts for Efficient Extraction of Mixed Rare Earths Oxides from Monazite Concentrates and their Potential Use as Dopant in High Temperature Coatings and Sintered Materials”
  2. Author: R.R.Piticescu
    oral presentation as a success story at Research & Innovation programme on Raw Materials to Foster Circular Economy, sectiunea III ERAMIN, 18.11. 2019, Bruxelles

  3. “Design, obtaining and characterisation of new materials based on zirconia doped with mixed rare earth oxide”
  4. Authors: S.N. Valsan, V.D. Dragut, M.Corban, M.L. Grilli, A.Rinaldi, D. Valerini, F.Balima, M.Prakasam, A. Largeteau, R.R.Piticescu.
    2nd International Conference on Emerging Technologies in Materials Engineering – EmergeMat, 6 - 8.11.2019, Bucuresti,
    ISSN 2602-0416

  5. “Design of New Coatings and Sintered Materials Based on Mixed Rare Earth Oxide”
  6. Authors: R.R. Piticescu, M. Corban, M.L.Grilli, F. Balima, M. Prakasam.
    oral presentation Nuclear Conference 2019, Mioveni, 03 - 04.06. 2019

  7. “Influence of Some REOs on The Zirconia Stabilization Process”
  8. Authors: N.A. Ghita, A.E. Slobozeanu, S.N. Valsan, V.D. Dragut, I. Csaki, C.Predescu.
    poster 11th International Conference on Materials Science & Engineering, BRAMAT 2019, Poiana Brasov, 13-16.03.2019

  9. “MONAMIX: New Concepts for Efficient Extraction of Mixed Rare Earths Oxides from Monazite Concentrates and their Potential Use as Dopant in High Temperature Coatings and Sintered Materials”
  10. Authors: R.R. Piticescu, A.E. Slobozeanu, S.Valsan, C.F.Ciobota, M.L.Grilli, M.Prakasam, A.Rinaldi, A. Sobetkii.
    EUROINVENT European Exhibition of Creativity and Innovation 11th Edition, Iasi 16 - 18.05 2019 (bronze medal)




1st PHASE (April - December 2018)


Results

      The main processing methods for separtion of rare earth oxides (REOx) from monazite concentrates were analyzed. From the 4 types of monazite concentrates existing in IMNR stock it was selected one with the highest ration between total REOs content and radioactive elements (Th,U). Researches for elaboration of the hydro-chemical processing laboratory technology to remove Th and U were started, using an alcaline technnology in autoclaves, in cooperation with an institute certified by National Commission for Controlling Nuclear Activities (CNCAN) for operating with such materials. The preliminary tests performed show that both Th and U were removed from the mixed REOs hydroxide cake with a good separation yield, proved by measuring the gamma doze of the purified product.


       

Fig. 1. Gamma Dozimetry measurements of purified hydroxyde cake

      In order to start preliminary tests for demonstration of potential use of mixed REOs as dopants, about 2 kg of zirconia powder doped with synthetic mixture of La, Y, Yb, Gd si Nd, having similar ratio with those existing in the monazite, were synhtesized at P1-IMNR by a hydrothermal process at temperatures >2000C and pressures 20-40 atm., using ammonia as mineralizing agent. Samples from the hydrothermally sythesized 8% REOs - doped ZrO2  powder were delivered to partners for future tests.
      Spark plasma sintering (SPS) experiments were performed by Spark Plasma Sintering system at P4-ICMCB CNRS, using the synthetic mixed REOs doped zirconia powders in comparison with commercial 8%Y2O3-doped zirconia. HP-SPS at 1.5 GPa and a temperature of 1250°C.  Pellets with densities around 96% of the theoretical value could be obtained, actually under tests for measuring their ionic conductivity for solid oxide fuel cells applications.
      For coatings development, P1-IMNR made first tests using the multiple EB-PVD pilot system, P3-P3-MGM made test coating with non-doped ZrO2 on Si, stainless steel and optical glass N-BK-7 samples by e-gun method on vacuum equipment BAK-600 BALZERS. The purpose is to test the ZrO2 evaporation by e-gun method, the optimum deposition rate and adhesion on different types of substrates.

     

Fig. 2. XRD pattern of 8% REOs-doped ZrO2 powders and SPS pellets and SEM picture of the pellet

      Partner 2-ENEA start preparing the RF-sputtering system to be used in coatings experiments, awaiting first REOs doped zirconia sintered targets to be delivered according to the work plan.


      Dissemination of the results
Book chapter: Nanostructured pure and doped Zirconia – Syntheses and Sintering for SOFC and optical applications
Authors: Mythili Prakasam, Sorina Valsan, Yiying Lu, Felix Balima, Wenzhong Lu, Radu Piticescu, Alain Largeteau
Published in Sintering Technology: Method and Application, ISBN 978-953-51-6802-7 INTECHOPEN for open access, http://dx.doi.org/10.5772/intechopen.81323

      Participation in international conferences

  1. “The use of mixed lanthanides as dopants for obtainig new materials” Authors: S.N.Valsan, C.F.Rusti, A.E.Slobozeanu, M.L.Grilli, M.Prakasam, A.Largeteau, R.R.Piticescu
  2. 1st International Conference on Emerging Technologies in Materials Engineering, Hotel Caro, Bucharest, 14-16 Nov.2018, poster
  3. “MONAMIX: New Concepts for Efficient Extraction of Mixed Rare Earths Oxides from Monazite Concentrates and their Potential Use as Dopant in High Temperature Coatings and Sintered Materials”
  4. Authors: S.N.Valsan, C.F.Rusti, A.E.Slobozeanu, M.L.Grilli, M.Prakasam, A.Largeteau, D.Valerini, A.Rinaldi, A.Sobetkii, R.R.Piticescu
    Raw Materials Week, Brussels, 12 Nov. 2018, poster