Indentation is one of the oldest method used by the engineers to indirectly measure the mechanical strength of materials. Among the various methods Brinell, Vickers and Rockwell hardness methods are quite popular methods used by the engineers. Each of them differ by the way in which the hardness is measured or the geometry of the indenter used. With the advent of instrumented indentation or depth sensing indentation technique, it is possible to obtain the hardness and elastic modulus of materials from the indentation experiments to a reasonable accuracy. Our group uses indentation techniques to understand the deformation mechanisms in several classes of materials e.g. ceramics, metals and amorphous materials. Besides this, our focus is to comprehensively investigate the plastic flow behavior underneath indentation using both experiments and simulations so as to address the inverse problems. Despite all these advancements, quantitative estimation of the deformation mechanisms under the indenter and comprehensive understanding of plastic flow under the indentation is still far from complete. A good understanding of the plastic flow beneath the indenter (from both experimental and theoretical stand point) will help in accurately predicting the elastic and plastic properties of materials as well as the underlying deformation mechanisms.
Relevant publications:
V. Kathavate, B. Praveen Kumar, I. Singh, K. Eswar Prasad, Analysis of Indentation Size Effect (ISE) in nanoindentation hardness in polycrystalline PMN-PT piezoceramics with different domain configurations, Ceramics International (Accepted 2021)
A. Sharma, Sree Harsha Nandam, H. Hahn, K. Eswar Prasad, On the differences in shear band characteristics between a binary Pd-Si metallic and nanoglass, Scripta Materialia 191 (2021) 17-22
V. Kathavate, H. Sonagara, B. Praveen Kumar, I. Singh, K. Eswar Prasad, Role of domain configurations on the Mechanistic Modelling of Indentation Size Effects (ISEs) in nano hardness of Hard and Soft PZT Piezoceramics, International Journal of Advances in Engineering Sciences and Applied Mathematics (accepted)
V. Kathavate, B. Praveen Kumar, I. Singh, K. Eswar Prasad, Effect of sub and above-curie temperature annealing on the nanomechanical properties of PMN-PT Piezoceramics , Ceramics International 46 (2020) 12876-12883
V. Kathavate, B. Praveen Kumar, P.R Choudhury, I. Singh, K. Eswar Prasad, Nanoindentation response of PZT and NKN-NT piezoceramics, Journal of Coupled Systems and Multiscale Dynamics (accepted, 2019)
K. Eswar Prasad, KT. Ramesh, Hardness and mechanical anisotropy of hexagonal SiC single crystal polytypes, Journal of Alloys and Compounds 770 (2019) 158-165.
K. Eswar Prasad, U. Ramamurty, Effect of temperature on the plastic zone and shear band density in a metallic glasses, Materials Science and Engineering A 535 (2012) 48-52.
K. Eswar Prasad, N. Chollacoop, U. Ramamurty, Role of indenter angle on the plastic deformation underneath the sharp indenter and representative strains: an experimental and numerical study, Acta Materialia 59 (2011) 4343-4355.
K. Eswar Prasad, Barun Das, U. Maitra, U. Ramamurty, C. N. R. Rao, Extraordinary synergy in the mechanical properties of polymer matrix composites reinforced with two nanocarbons, Proceedings in National Academy of Sciences 106 (2009) 13186.
U. Maitra, K. Eswar Prasad, C. N. R. Rao, U. Ramamurty, Mechanical properties of nanodiamond reinforced polymer-matrix composites, Solid State Communications 149 (2009) 1693-1697.