Gaurav Mohanty

Tutkimukseni keskittyy materiaalien mikro- ja nanomittakaavan muodonmuutoksiin. Hyödynnämme pyyhkäisyelektronimikroskopiaa ja kohdennettua ionisuihkuteknologiaa (focused ion beam, FIB), joiden avulla tutkimme mikromittakaavan koekappaleita ja niiden mekaanisia ominaisuuksia erilaissa olosuhteissa, muun muassa kryogeenisissä ja ultrakorkeissa lämpötiloissa (-150 - 1000°C) ja eri muodonmuutosnopeuksilla (0.0001- 10,000 /s). Tavoitteena on lisätä ymmärrystä materiaalien muodonmuutosmekanismeista ja mekaanisesta käyttäytymisestä. Kehitämme myös uusia kokeellisia menetelmiä materiaalien väliaikaisten muodonmuutosten ja väsymisen testaukseen. Tutkimusryhmäni tutkii lämpötilan ja muodonmuutosnopeuden vaikutuksia metalleissa, metalliseoksissa, puolijohteissa, keraamimateriaaleissa, ohutkalvoissa ja pinnoitteissa.  

- materiaalien plastisuus pienessä mittakaavassa 

- materiaalien mikromekaniikka 

- korkeissa lämpötiloissa ja suurilla nopeuksilla tapahtuvat materiaalien muodonmuutokset 

- materiaalien väliaikaiset muodonmuutokset (muodonmuutosnopeuden vaihtelu, jännitysrelaksaatio ja virumiskokeet)

- suuren kuormanvaihtoluvun väsyminen

- materiaalien muodonmuutosten mekanismit

- kombinatorinen materiaalitiede

Materiaalitiede ja ympäristötekniikka

Mikromekaniikka korkeissa ja kryogeenisissä lämpötiloissa: 

- G. Mohanty, M. Conte, J. Schwiedrzik, J.M. Wheeler, B. Bellaton, J. Michler, N.X. Randall, Novel high temperature vacuum nanoindentation system with active surface referencing and non-contact heating for measurements up to 800° C, Review of Scientific Instruments, 90 (2019) 045105

- K. Thomas, G. Mohanty, J. Wehrs, A.A. Taylor, S. Pathak, D. Casari, J. Schwiedrzik, N. Mara, R. Spolenak, J. Michler, Elevated and cryogenic temperature micropillar compression of magnesium–niobium multilayer films, Journal of Materials Science, 54 (2019) 10884

- T.E.J. Edwards, F. Di Gioacchino, A.J. Goodfellow, G. Mohanty, J. Wehrs, J. Michler, WJ. Clegg, Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression, Acta Materialia, 166 (2019) 166

- T.E.J. Edwards, F. Di Gioacchino, G. Mohanty, J. Wehrs, J. Michler, WJ. Clegg, Longitudinal twinning in TiAl alloy at high temperature by in situ microcompression, Acta Materialia, 148 (2018) 202-215

Tilapäiset muodonmuutokset (muodonmuutosnopeuden herkkyys ja jännitysrelaksaatio): 

- K. Thomas, G. Mohanty, J. Wehrs, A.A. Taylor, S. Pathak, D. Casari, J. Schwiedrzik, N. Mara, R. Spolenak, J. Michler, Elevated and cryogenic temperature micropillar compression of magnesium–niobium multilayer films, Journal of Materials Science, 54 (2019) 10884

- G. Mohanty, J. Wehrs, B.L. Boyce, M. Hasegawa, L. Philippe, J. Michler, Room temperature stress relaxation in nanocrystalline Ni measured by micropillar compression and miniature tension, Journal of Materials Research, 31 (2016) 1085-1095

- G. Mohanty, J.M. Wheeler, R. Raghavan, J. Wehrs, M. Hasegawa, S. Mischler, L. Philippe, J. Michler, Elevated temperature, strain rate jump microcompression of nanocrystalline Nickel, Philosophical Magazine, 95 (2015) 1878-1895 Special Issue: Nano-mechanical Testing in Materials Research and Development IV

- J. Wehrs, G. Mohanty, G. Guillonneau, A.A. Taylor, X. Maeder, D. Frey, L. Philippe, S. Mischler, J.M. Wheeler, J. Michler, Comparison of in-situ micromechanical strain rate sensitivity measurement techniques, JOM 67 (2015) 1684-1693, Special topic collection: In Situ Mechanical Testing in Electron Microscopes

Murtuminen: 

- J. Ast, M.N. Polyakov, G. Mohanty, J. Michler, X. Maeder, Interplay of stresses, plasticity at crack tips and small sample dimensions revealed by in-situ micro-cantilever tests in tungsten, Materials Science and Engineering A, 710 (2018) 400-412

- J. Ast, G. Mohanty, Y. Guo, J. Michler, X. Maeder, In situ micromechanical testing of tungsten micro-cantilevers using HR-EBSD for the assessment of deformation evolution, Materials and Design, 117 (2017), 265-266

- A.J.G. Lunt, G. Mohanty, T. K. Neo, J. Michler, A.M. Korsunsky, Microscale resolution fracture toughness profiling at the zirconia-porcelain interface in dental prostheses, Proceedings of SPIE, 9668 (2015) 96685S1-11D. 

- J. Zechner, G. Mohanty, C. Frantz, L. Philippe, J. Michler, Mechanical properties and interface toughness of metal filled nanoporous anodic alumina coatings on aluminum, Surface and Coatings Technology 260 (2014) 246-250 

Elektronien takaisinsirontadiffraktio (EBSD) ja synkrotronisäteilyyn perustuva röntgenteknologia: 

- J. Gamcová, G. Mohanty, Š. Michalik, J Wehrs, J. Bednarčík, C. Krywka, J.M. Breguet, J. Michler, H. Franz, Mapping strain fields induced in Zr-based bulk metallic glasses during in-situ nanoindentation by X-ray nanodiffraction, Applied Physics Letters, 108 (2016) 031907 1-4

- J. Ast, M.N. Polyakov, G. Mohanty, J. Michler, X. Maeder, Interplay of stresses, plasticity at crack tips and small sample dimensions revealed by in-situ micro-cantilever tests in tungsten, Materials Science and Engineering A, 710 (2018) 400-412

- J. Ast, G. Mohanty, Y. Guo, J. Michler, X. Maeder, In situ micromechanical testing of tungsten micro-cantilevers using HR-EBSD for the assessment of deformation evolution, Materials and Design, 117 (2017), 265-266

Ohutkalvot ja pinnoitteet: 

- Z. Liao, M. Polyakov, O.G. Diaz, D. Axinte, G. Mohanty, X. Maeder, J. Michler, M. Hardy, Grain Refinement Mechanism of Nickel-Based Superalloy by Severe Plastic Deformation-Mechanical Machining Case, Acta Materialia, 180 (2019) 2

- K. Thomas, G. Mohanty, J. Wehrs, A.A. Taylor, S. Pathak, D. Casari, J. Schwiedrzik, N. Mara, R. Spolenak, J. Michler, Elevated and cryogenic temperature micropillar compression of magnesium–niobium multilayer films, Journal of Materials Science, 54 (2019) 10884

- A.H.S. Iyer, G. Mohanty, K. Stiller, J. Michler, M.H. Colliander, Microscale fracture of chromia scales, Materialia, 8 (2019) 100465

- M. Hasegawa, G. Guillonneau, G. Mohanty, X. Maeder, J. Wehrs, J. Michler, L. Philippe, Electrodeposition of dilute Ni-W alloy with enhanced thermal stability: accessing nanotwinned to nanocrystalline microstructures, Materials Today Communications, 12 (2017) 63-71

- M. Hadad, H. Ashraf, G. Mohanty, J. Michler, C. Sandu, P. Muralt, Key-features in processing and microstructure for achieving giant electrostriction in gadolinium doped ceria thin films, Acta Materialia, 118 (2016) 1–7

Keraamiset materiaalit:

- A.J.G. Lunt, G. Mohanty, S. Ying, J. Dluhoš, T. Sui, T.K. Neo, J. Michler, A.M. Korsunsky, A Comparative Transmission Electron Microscopy, Electron Diffraction Spectroscopy and Spatially Resolved Micropillar Compression Study of the Yttria Partially Stabilised Zirconia–Porcelain Interface in Dental Prosthesis, Thin Solid Films 596 (2015) 222-232 

- A.J.G. Lunt, G. Mohanty, T. K. Neo, J. Michler, A.M. Korsunsky, Microscale resolution fracture toughness profiling at the zirconia-porcelain interface in dental prostheses, Proceedings of SPIE, 9668 (2015) 96685S1-11D. 

- M.I. Ahmed, G. Mohanty, K. Rajan, M. Akinc, Crystal growth and mechanical characterization of ZrMo2O8, Journal of Crystal Growth 404 (2014)100-106

- M.I. Ahmed, G.Mohanty, L.R. Cambrea, D.C. Harris, K. Rajan, M. Akinc, Crystal growth of ZrW2O8 and its optical and mechanical characterization, Journal of Crystal Growth, 343 (2012) 115-121

Polymeerimateriaalit: 

- A.A. Leal, G. Mohanty, F.A. Reifler, J. Michler, R. Hufenhaus, Mechanical response of melt-spun amorphous filaments, Science and Technology of Advanced Materials, 15 (2014) 035016 1-11

- Esqué-de los Ojos, R. Ghisleni, A. Battisti, G. Mohanty, J. Michler, J. Sort, A.J. Brunner, Understanding the mechanical behavior of fiber/matrix interfaces during push-in tests by means of finite element simulations and a cohesive zone model, Computational Materials Science, 117 (2016) 330–337

Materiaalikehitys, combinatorial composition gradients ja informatiikka: 

- M. Hasegawa, G. Guillonneau, G. Mohanty, X. Maeder, J. Wehrs, J. Michler, L. Philippe, Electrodeposition of dilute Ni-W alloy with enhanced thermal stability: accessing nanotwinned to nanocrystalline microstructures, Materials Today Communications, 12 (2017) 63-71 

- G. Gamez, G. Mohanty, J. Michler, Ultra-fast Elemental Mapping of Materials Combinatorial Libraries and High-throughput Screening Samples via Pulsed Glow Discharge Optical Emission Spectroscopy, Journal of Analytical Atomic Spectrometry, 28 (2013) 1016-1023

- G. Gamez, G. Mohanty, J. Michler, Image Denoising Techniques Applied to Glow Discharge Optical Emission Spectroscopy Elemental Mapping, Journal of Analytical Atomic Spectrometry, 29 (2014), 315-323.

- C.G. de Vega, D. Alberts, V. Chawla, G. Mohanty, I. Utke, J. Michler, R. Pereiro, N. Bordel, G. Gamez, Use of radiofrequency power to enable glow discharge optical emission spectroscopy ultrafast elemental mapping of combinatorial libraries with nonconductive components: nitrogen-based materials, Analytical and bioanalytical chemistry 406 (2014) 7533-7538

- G. Mohanty, L. Besra, S, Bhattacharjee, B.P. Singh, Optimization of electrophoretic deposition of alumina onto steel substrates from its suspension in iso-propanol using statistical design of experiments, Materials Research Bulletin, 43 (2008) 1814-1828