Department of Metallurgical & Materials Engineering

&ldquo;IIT Jodhpur is committed to impart quality education to facilitate the creation of qualified, competent and responsible human resources to meet the emerging technological challenges of the world. It is working towards creating an equitable learning platform that is positive, accessible and effective in the face of the modern societal and scientific advancements.

Flexibility in curriculum, in all its academic programs, encompassing elements of teaching, research, creativity, innovation and entrepreneurship is the most unique feature of IIT Jodhpur. The Department of Science and Technology (DST), under the National Mission on Cyber Physical Systems, has identified IIT Jodhpur as a Technology &amp; Innovation Hub in the area of Augmented Reality and Virtual Reality. The institute has also been nominated as the coordinator for the Jodhpur City and Knowledge Cluster by the Office of Principal Scientific Adviser, Government of India.

The sprawling 852-acre IIT Jodhpur campus is a majestic tribute to the deep-rooted diverse cultural heritage of the region. The campus is an architectural masterpiece, which is slated to become an international exemplar of sustainability with net-zero energy, and advanced water and waste management strategies.&rdquo;

IIT Jodhpur

A wide range of superplastic materials were investigated for their high temperature flow property characteristics. Depending on the ranges of strain rates, temperatures and grain sizes, there appear 2–3 regimes of stress–strain rate relationship, with distinct values of strain rate sensitivity index, activation energy for deformation and grain size exponent. These parameters of constitutive relationship are significantly influenced by concurrent microstructure evolution, which includes grain growth, grain refinement, dislocation dynamics, texture modification, twinning and cavity formation. An attempt was made to evaluate the contribution of such changes to modify the constitutive relationship for high temperature deformation. © 2015, The Indian Institute of Metals - IIM.

Transactions of the Indian Institute of Metals

Overview: Experimental Constitutive Relationship for High Temperature Deformation and the Effect of Concurrent Microstructure Evolution

Wavy roll design was employed for strengthening 1 mm thin austenitic stainless steel coil sheet by cold rolling without further reduction in thickness. This steel possesses high corrosion resistance and high ductility. Initially, the sheets were rolled into sine wave shape (wave amplitude <2 mm) and then flattened using conventional cold rolling mill. Such a process cycle was repeated for four times successfully and the mechanical properties were measured after each cycle. The yield strength increased from 255 to 931 MPa with corresponding decrease in elongation from 45% to only 17% after the fourth cycle of severe cold working. Tensile strength and hardness values increased from 753 MPa and 185 HV to 973 MPa and 371 HV, respectively. The micro-to-nano-scale resolution structures, obtained by optical and atomic force microscope (AFM), were used to explain the variation in properties during this manufacturing process and to propose schematically the deformation mechanism. Copyright © Taylor & Francis Group, LLC.

World University root node

Materials and Manufacturing Processes

A Process of Notch Wavy Rolling for Strengthening Metal Sheets

High temperature flow behavior of Al-6.65Si-0.44Mg (all in wt%) (A356) alloy and A356+5wt% B4C composite were investigated by compression test at temperatures 470, 500, 530 and 570°C and strain rates 10-3, 10-2, 10-1 and 1s-1. Constitutive relationship was established by the prediction of materials constants α, β, n, Q and lnA. The variations in stable and instable regions of processing map were investigated in A356 alloy and A356+5wt% B4C composite. It was found that the existence of instability domain for A356 alloy, over the range of temperatures ~510-570°C and strain rates ~1- 4×10-2s-1, was extended to regime of temperatures ~470-570°C over the same strain rates upon 5% B4C reinforcement. The microstructural evolutions by stable and instable regions were studied in scanning electron microscope (SEM) and by the electron backscatter diffraction (EBSD) technique. © 2016 Elsevier B.V.

Materials Science and Engineering A

Development of constitutive relationship and processing map for Al-6.65Si-0.44Mg alloy and its composite with B4C particulates

Separate compression samples of VT20 Ti-alloy Ti-5.9A1-2.1Zr-1.6V-1.4Mo (wt%), charged with 0, 0.15 and 0.36 wt%H, were deformed to true strain of 0.70 at a strain rates of 1×10-3 and 1×10-1 s-1 at test temperatures of 600 and 850 °C. H charging led to the varying microstructures ranging from equiaxed to lamellar ones depending on H level. In the course of deformation, their occurred refinement of microstructures with reduced interlamellar spacing depending on the test conditions. The contributions of these sources to microstructure evolution and flow properties were examined in an attempt to explore some correlation between them. An attempt is made to understand the effect of H present on the microstructure and flow properties to account for the variations in the parameters of the constitutive relationship.

TMS Annual Meeting

Effect of concurrent microstructure evolution and hydrogen level on flow behavior of near alpha Ti-alloy

The present study reports the fabrication of Al-4.4Cu/2TiB2 nanocomposite from its microcomposite via post in-situ reaction ultrasonic treatment (UT). For the purpose of accomplishing post in-situ reaction ultrasonic treatment, the in-situ formed Al-4.4Cu/2TiB2 microcomposite was remelted and subjected to high-intensity ultrasonic waves for various length of time. Post in-situ reaction ultrasonic treatment of Al-4.4Cu/2TiB2 composite has resulted significant reduction in the size of TiB2 particles down to nano range. Ultrasonic cavitation aided particle dissolution and re-precipitation has been proposed as a mechanism responsible for the substantial reduction of TiB2 particle size. The compressive yield strength of Al-4.4Cu/2TiB2 nanocomposite formed via formed post in-situ reaction ultrasonic treatment is approximately two times higher than that of Al-4.4Cu alloy. The improved mechanical property of nanocomposite has been attributed to the presence of TiB2 particles of nanometer size and robust interfaces with the aluminum alloy. © 2016 Elsevier B.V.

Journal of Alloys and Compounds

Post in-situ reaction ultrasonic treatment for generation of Al-4.4Cu/TiB2 nanocomposite: A route to enhance the strength of metal matrix nanocomposites

Microstructural evolution of cold-rolled Cu–5%Zn alloy during in situ heating inside field-emission scanning electron microscope was utilized to obtain user-independent parameters in order to trace the progress of static recovery and recrystallization. Electron back-scattered diffraction (EBSD)-based orientation imaging microscopy was used to obtain micrographs at various stages of in situ heating. It is shown that unlike the pre-existing methods, additional EBSD-based parameter can be used to trace the progress of recovery and recrystallization, which is not dependent on user input and hence less prone to error. True strain of 0.3 was imposed during cold rolling of alloy sample. Rolled sample was subjected to in situ heating from room temperature to 500°C (∼0.58 Tm) with soaking time of 10 min, at each of the intermediate temperatures viz. 100, 200, 300, 400 and 450°C. After reaching 500°C, the sample was kept at this temperature for a maximum duration of around 15 h. The sample showed clear signs of recovery for temperature up to 450°C, and at 500°C, recrystallization started to take place. Recrystallization kinetics was moderate, and full recrystallization was achieved in approximately 120 min. We found that EBSD parameter, namely, band contrast intensity can be used as an extra handle to map out the progress of recrystallization occurring in the sample. By contrast, mean angular deviation can be used to understand the evolution of recovery in samples. The parameters mentioned in the current study, unlike other pre-existing methods, can also be used for mapping local microstructural transformations due to recovery and recrystallization. We discuss the benefits and limitations in using these additional handles in understanding the changes taking place in the material during in situ heating. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society

Journal of Microscopy

User-independent EBSD parameters to study the progress of recovery and recrystallization in Cu–Zn alloy during in situ heating

We report on detailed microstructural and atomic ordering characterization by transmission electron microscopy in epitaxial LiFe5O8 (LFO) thin films grown by chemical vapor deposition (CVD) on MgO (001) substrates. The experimental results of LFO thin films are compared with those for bulk LFO single crystal. Electron diffraction studies indicate weak long-range ordering in LFO (α-phase) thin films in comparison to bulk crystal where strong ordering is observed in optimally annealed samples. The degree of long-range ordering depends on the growth conditions and the thickness of the film. Annealing experiment along with diffraction study confirms the formation of α-Fe2O3 phase in some regions of the films. This suggests that under certain growth conditions γ-Fe2O3-like phase forms in some pockets in the as-grown LFO thin films that then convert to α-Fe2O3 on annealing. © 2016 Elsevier B.V. All rights reserved.

Structural characterization of epitaxial LiFe5O8 thin films grown by chemical vapor deposition

The mineral eldfellite, NaFe(SO4)2, was recently proposed as an inexpensive candidate for the next generation of cathode application in Na-based batteries. Employing the density functional theory framework, we have investigated the phase stability, electrochemical properties and ionic diffusion of this eldfellite cathode material. We showed that the crystal structure undergoes a volume shrinkage of ≈8% upon full removal of Na ions with no imaginary frequencies at the Γ point of phonon dispersion. This evokes the stability of the host structure. According to this result, we proposed structural changes to get higher specific energy by inserting two Na ions per redox-active metal. Our calculations indicate NaV(SO4)2 as the best candidate with the capability of reversibly inserting two Na ions per redox center and producing an excellent specific energy. The main bottleneck for the application of eldfellite as a cathode is the high activation energies for the Na+ ion hop, which can reach values even higher than 1 eV for the charged state. This effect produces a low ionic insertion rate. © The Royal Society of Chemistry.

Journal of Materials Chemistry A

Unveiling the thermodynamic and kinetic properties of Na x Fe (SO 4) 2 (x= 0–2): toward a high-capacity and low-cost cathode material

Scientific reports

Static and dynamical properties of heavy actinide monopnictides of lutetium

This work underlines the easy use of thermodynamics-based approach in identifying the glass forming systems. In this work, a simple and effective thermodynamic model named GCE is devised to numerically predict easy glass forming compositions. Further, to validate its reliability, co-relation of GCE with the Miedema model, PHSS model, critical diameter, Turnbull's reduced glass transition temperature and Inoue supercooled liquid region in V-Ti-Cr, Zr-Cu-Ag, Mg-Zn-Ca, Ca-Mg-Cu and Cu-Zr systems respectively is demonstrated. The model co-related well, and therefore the calculations based on this model are well-capable of anticipating the glass forming compositions. With a proven accuracy for the prediction, this proposed model can be used as an efficient tool for alloy-designing. © 2014 Elsevier B.V. All rights reserved.