Education

  • Ph.D., New Mexico Institute of Mining and Technology, 1984
  • M.S., South Dakota School of Mines and Technology, 1981
  • B.E., University of Rajasthan, India, 1980

Research Areas and Descriptors

  • High-strain-rate mechanical properties, Shock-compression, Shock induced physical and chemical changes, Dynamic Compaction of Powders, Energetic Materials, Phase transformations, non-equilibrium processing, metallic glasses, nanocrystalline alloys, Dynamic fracture

Background

Dr. Thadhani joined the faculty in the School of Materials Science and Engineering at Georgia Tech in September, 1992. His research focuses on studies of shock-induced physical, chemical, and mechanical changes for processing of novel materials and for probing the deformation and fracture response of metals, ceramics, polymers, and composites, subjected to high-rate impact loading conditions. He has developed state-of-the-art high-strain-rate laboratory which includes 80-mm and 7.62-mm diameter single-stage gas-guns, and a laser-accelerated thin-foil set-up, to perform impact experiments at velocities of 70 to 1200 m/s. The experiments employ time-resolved diagnostics to monitor shock-initiated events with nanosecond resolution employing piezoelectric and piezoresistive stress gauges, VISAR interferometry, Photonic-doppler-velocimetry, and high-speed digital imaging, combined with the ability to recover impacted materials for post-mortem microstructural characterization and determination of other properties. He has built computational capabilities employing continuum simulations for design of experiments and development and validation of constitutive equations, as well as for meso-scale discrete particle numerical analysis (using CTH and ALE3D codes) to determine the effects observed during shock compression of heterogeneous materials, using real microstructures.

Research

His current research projects (pictured below) include (a) dynamic shock consolidation of nano-sized and nanocrystalline powders for fabrication of bulk nanocomposite permanent magnets with high energy products; (b) design, processing, characterization and evaluation of structural energetic materials (based on intermetallics, ceramics, thermites, and polymer-composites) and including determining their pressure-volume compressibility characteristics and constitutive mechanochemical behavior; (c) Phase transition and high strain rate mechanical properties of bulk metallic glasses and their composites; and (d) development and validation of constitutive models for high-strain-rate mechanical property characterization of various fcc, bcc, and hcp metals.

Dr. Thadhani is a fellow of the American Physical Society (APS) and of ASM International. He is author of more than two hundred publications in journals and proceedings, including several authoritative reviews and book articles. He is Editor of Springer Series on Shock Compression, Associate Editor of Shock Waves: An International Journal, Key Reader for Metallurgical and Materials Transactions, Past Chair of the APS-SCCM Awards committee, and Past President of the Alpha Sigma Mu, Materials Honor Society. He has served as a consultant for various industries, and has been on advisory boards and organizing committees for many international conferences.

Dr. Thadhani’s current research group includes a principal research scientist, post-doctoral research fellow, eleven Ph.D. student, and three undergraduate students. He has graduated more than 30 Ph.D. and M.S. students.

 

Distinctions

  • Associate Editor of Shock Waves: An International Journal, 2007-present
  • American Physical Society Fellow, 2007
  • Alpha Sigma Mu (Materials Honor Society) Board of Trustees President, 2006-2007
  • ASM International, The Materials Information Society, Fellow, 2000
  • Metallurgical and Materials Transactions A (MMT-A), Key Reader, 1996-present
  • Joint Cmmission for MMT-A, Chair, 2003-2004
  • Georgia Intern/Fellowships for Teachers at Georgia Tech Executive Board Member, 2003-present
  • American Physical Society, Shock Compression of Condensed Matter Topical Group Executive Committee Elected Member, 2005 and Chair of Awards Selection Committee, 2006-2007.

Publications

  • N.N. Thadhani, "Shock-induced Chemical Reactions and Synthesis of Materials," Progress in Materials Science, Vol. 27 (2), pp. 117-226, 1993.
  • N.N. Thadhani, "Mechanisms of Shock-Assisted and Shock-Induced Chemical Reactions in Elemental Powder Mixtures," J. of Applied Physics, Vol. 76 (4), pp. 2129 -2138, 1994.
  • N.N. Thadhani, R.A. Graham, T. Royal, E. Dunbar, M.U. Anderson, and G.T. Holman, Shock-induced Chemical Reactions in Ti-Si Powder Mixtures: Time-Resolved Pressure Measurements and Materials Analysis, Journal of Applied Physics, Vol. 82
  • (3), (1997) pp. 1113-1128.
  • Z.Q. Jin, K.H. Chen, J. Li, H. Zeng, S-F. Cheng, J.P. Liu, Z.L. Wang, N.N. Thadhani, “Shock compression response of magnetic nanocomposite powders,” ACTA MATER. 52: (8) 2147-2154 2004
  • D. Eakins, N.N. Thadhani, Instrumented Anvil-On-Rod Impact Tests for Validating Applicability of Standard Strength Models to Transient Deformation States, Journal of Applied Physics, Vol. 100, No. 7, 2006, pp. 073503-1-8.
  • D. Eakins and N.N. Thadhani, “Shock-Induced Reaction In A Flake Nickel + Spherical Aluminum Powder Mixture”, Journal of Applied Physics, V. 100, No. 11, 2006, pp. 113521-25.
  • D. Eakins and N.N. Thadhani, “Discrete Particle Simulation of Shock Wave Propagation in a Binary Ni+Al Powder Mixture”, Journal of Applied Physics, 2007, Vol. 101 (200) 043508-18.
  • M. Martin, T. Sekine, T. Kobayashi, L. Kecskes, and N.N. Thadhani, High Pressure Equation of State of a Zirconium-Based Bulk Metallic Glass, Metallurgical and Materials Transactions, Vol. 38A(11), (2007), pp. 2689-2696.
  • L. Ferranti and N.N. Thadhani, “Dynamic Mechanical Behavior Characterization of Epoxy -Cast Al+Fe2O3 Thermite Mixtures,” Metallurgical and Materials Transactions, Vol. 38A(11), (2007), pp. 2697-2715.
  • C. Dai, D.Eakins, and N.N. Thadhani, “Dynamic Densification Behavior of nano-iron powders under shock compression,” Journal of Applied Physics, 103 (9), 2008, Article No. 093503.
  • D.E. Eakins and N.N. Thadhani, “The Shock Compression of Reactive Powder
  • Mixtures,” Invited Review Article, International Materials Reviews, Vol. 54, No. 4, (2009), pp. 181-213.
  • M. Martin, L. Meyer, L. Kecskes, N.N. Thadhani, “Uniaxial and biaxial compressive response of a bulk metallic glass composite over a range of strain rates and temperatures,” Journal of Materials Research, Vol. 24 (1), 2009, pp. 66-78.
  • C. Dai and N.N. Thadhani, “Shock compression response of magnetic Fe3O4 nanoparticles,” Acta Materialia, Vol. 59, No. 2, 2011, pp. 785-796.
  • E. Herbold, N.N. Thadhani, J.L. Jordan, “Effects of processing and powder size on microstructure and reactivity in arrested reactive milled Al+Ni,” Acta Materialia, Vol. 59 (17), October 2011 pp.6717-6728.
  • C. Wehrenberg, S.G. Shankar, NN. Thadhani, “Mechanically induced phase transition in Fe4N during ball milling and shock compression of powders,” Materials Science and Engineering - A, Vol. 528, 13-14, pp. 4837-4839, 2011.