New Proposals submitted.

S.No. Number Start Date End Date Project Leader Category Type Core Area/ Sub Area Status/ Action/ Resubmission/ Reason for Cancel
1NML/IPSG/2017/2018/89632017-04-012018-03-31Rajesh Kumar RaiR&DFull tenure(1 year)Materials Evaluation/ Mechanical Behaviour of Materialsreview/ submit

Title: High Temperature Mechanical Deformation and Fracture Behavior of Nickel Based Super-alloys (module III).

Abstract: The CM 247 alloy is designed primarily for directionally solidified turbine blade and vane applications. Directional solidification (DS) reduces the number of grain boundaries transverse to the primary loading axis, obtaining improved creep resistance. In DS blades the [001] crystallographic orientation is the preferred orientation along the blade principal axis. During service condition, these components are exposed to severe stress conditions and temperature fluctuation. These service conditions induce low cycle fatigue, creep and creep-fatigue damage in the material. The present proposal aims at studying creep-fatigue interaction behaviour of CM 247 DS nickel base superalloys at temperatures above 750oC and 850oC and studying the microstructural changes through extensive scanning and transmission electron microscopy.

2NML/IPSG/2018/2019/271062018-10-012019-09-30Dr Krishnendu MukherjeeThematic ResearchFull tenure(1 year)Materials Evaluation/ Materials Modelingreview/ submit

Title: Ab initio Modelling of deformation anisotropy in BCC ferrite using Density Functional Theory (DFT)

Abstract: In case of bcc metals the deformation occurs mainly by slip of screw dislocations in {110} and {112} planes. The Critically resolved shear stress (CRSS) of bcc metals depends on the angle between maximum resolved shear stress plane (MRSSP) and the slip plane (χ), the direction of slip, and the non-glide stress. These lead to anisotropy in deformation behaviour of the material. These anisotropies are know as Twinning/Anti-Twinning (T/AT) assymetry and assymetry due to non-glide stresses. As a consequence, the Peierls Barrier changes according to the loading direction (which in turn dictates the angle χ) and the value of non-glide stress. As, the dislocation has to climb the Peierls barrier to move from a stable location to the next stable location, the anisotropies discussed above relates to anisotropic deformation behaviour of bcc metals. In this work it is proposed to develop a Density Functional Theory (DFT) based ab initio model to quantify the Peierls Barrier, which can be correlated to the CRSS for movement of screw dislocations in bcc metals. The model is based on the Kohn-Sham density functional approach with appropriate exchange-correlation functional. The model will be implemented in open source/commercial DFT code to calculate the electronic structure and corresponding CRSS for bcc metals.

3NML/IPSG/2018/2019/598792018-11-012019-10-31Dr. Jay ChakrabortyScholastic ResearchFull tenure(1 year)Materials Engineering/ Advanced Materials (Structural, Bio, Magnetic) & Preview/ submit

Title: Graphene based high strength steel: Can graphene effectively block the dislocation movement ?

Abstract: In the present research proposal, 'Graphene', a 2D form of carbon has been proposed to strengthen a 3D bulk material like conventional steel. It is interesting to note that in recent years, elastic and plastic properties graphene has been exploited to make metal-graphene nanolayer composite coating (for details, please see Nature communication (2013) (DOI:10.1038/ncomms3114)). Fundamentally, all strengthening mechanisms aims to hinder the dislocation motion in the materials during plastic deformation. A graphen based composite steel has been proposed where we address question whether graphene effectively can block the dislocation movement ? Molecular dynamics simulation will be performed in order to understand the dislocation motion at the interface of steel and graphene. Experimental proof of concept will be carried out by making a sandwich of ferrite/graphene/ferrite composite steel assembly and then performing the mechanical testing of the whole assembly. Detailed X-ray diffraction (XRD) and crosssectional transmission electron microscopy (TEM) of the composite steel will be performed in order to analyze the phase and dislocation microstructure at the ferrite/graphene interface.