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

Strain-controlled low-cycle fatigue (LCF) data have been generated on 9Cr-1Mo thick-section (300 mm) tube plate forgings under simulated postweld heat treatment conditions at 723, 773 and 793 K employing a constant strain rate of 1 × 10-3 s-1. LCF tests were performed over strain amplitudes in the range ±0.25 to 1.00%. The fatigue life was found to decrease with increasing temperature. The effect of temperature was more pronounced at low strain amplitudes. Within the range of strain amplitudes examined, the experimental data on fatigue life at elevated temperatures were found to match well with the life predicted by the Tomkins crack growth model. Tentative fatigue design curves for elevated temperatures have been formulated for 9Cr-1Mo based on information generated in the laboratory using the philosophy outlined in the ASME code case N-47. A fatigue design curve applicable for the temperature range 300-644 K was computed based on room temperature tensile properties, incorporating the concept of fatigue limit and mean stress. © 1992.

World University root node

International Journal of Fatigue

Development of fatigue design curves for thick-section 9Cr-1Mo ferritic steel forgings

Dual phase (martensite + δ-ferrite) microstructures were developed in a modified 9Cr-1Mo steel, by austenitising at 1523-1623 K, followed by water-quenching. These duplex structures were thermally aged at 973 K for ageing periods varying from 30 min to 21 h. Morphological aspects of δ-ferrite phase and its response to age-hardening were studied by optical, scanning electron and transmission electron microscopy, X-ray diffraction, electron probe microanalysis and microhardness testing. It was observed that austenitizing at 1523 K produced fine, acicular δ-ferrite while the δ-ferrite formed by austenitising at higher temperatures (1573-1623 K) were massive, irregular-shaped and banded. Moreover the presence of 8-ferrite caused an abnormally strong (110) reflection, observed in X-ray diffraction patterns of martensite plus δ-ferrite structures. This behaviour is thought to be due to development of (110) texture in δ-ferrite phase. Thermal ageing at 973 K caused age-hardening of δ-ferrite with a peak hardness attained after 3.6 ks of ageing. Electron microscopic results suggest that the observed hardening was caused by the formation of Fe2Mo Laves phase. © 1992.

Journal of Nuclear Materials

The morphology and ageing behaviour of δ-ferrite in a modified 9Cr-1Mo steel

The effect of boron content on the grain growth behaviour of type 316L stainless steel was investigated by annealing for 0.25-100 h at 950°C and by isochronal annealing for 1 h between 900 and 1300 °C. Grain growth is enhanced by boron. Activation energies for grain growth are found to be 52 and 317 kJ mol-1 in the lower and higher temperature range respectively. © 1992.

Materials Science and Engineering A

Grain growth behaviour of type 316L stainless steel

Grain growth behaviour of the Al-Cu eutectic alloy was investigated as a function of strain (ε), strain rate {Mathematical expression} and deformation temperature (T) over {Mathematical expression} = 10-2 s-1 and T=400 to 540°C. The grain size increases with increase in strain and temperature. Upon deformation to a fixed strain, the grain growth is generally seen to be more at lower strain rates. The rates of overall grain growth {Mathematical expression} and due to deformation alone {Mathematical expression}, however, increase with increasing strain rate according to {Mathematical expression} and {Mathematical expression}, respectively. The increase in the grain growth rate with strain rate is attributed primarily to the shorter time involved at higher strain rate for reaching a fixed strain. The activation energy for grain growth under superplastic conditions is estimated to be 79 kJ mol-1. © 1991 Chapman &amp; Hall.

Journal of Materials Science

Grain growth behaviour of the Al-Cu eutectic alloy during superplastic deformation

Journal of Materials Science Letters

Microstructural evolution in a superplastic Pb-Sn eutectic alloy

Grain growth behaviour of an α/β brass

Scripta Metallurgica et Materiala

On the Hall-Petch relationship in type 316L stainless steel at room temperature

Cavitation behavior upon deformation of an Al-Cu eutectic alloy was studied by densitometry and quantitative microscopy. Tensile specimens were strained to different strain levels at constant strain rates and temperatures over the range of 10-5 to 10-2 s-1 and 400° to 540 °C, respectively. The cavity volume increased with increasing strain and strain rate but decreased with increasing temperature. The increase in cavity volume occurred through an increase in both the number and size of cavities. The cavities were spherical in most of the cases, which was attributed to the diffusion-controlled cavity growth mechanism and its modification when the cavity size reaches the size of a grain. The number and volume of cavities were used to evaluate the nature of the cavity nucleation rate and the level of pre-existing cavities. © 1989 The Minerals, Metals &amp; Materials Society and ASM International.

Metallurgical Transactions A

Cavitation behavior of an Al-Cu eutectic alloy during superplastic deformation

Tensile specimens of type 316L stainless steel with a grain size of 5.0 μm have been deformed at a constant strain rate of 10−3 s−1 over the temperature range 21–900°C and by differential strain-rate test technique over strain rates from about 10−5 to 10−3 s−1 at temperatures in the range 750–900°C. The normalized yield and flow stresses against temperature plots exhibit three regions. While in regions I and III the stresses decrease with increasing temperature, they increase with increasing temperature in region II. Transmission electron microscopy studies on deformed specimens show that at small strains the dislocations generated at grain boundaries have characteristic distributions: in region I the dislocations are confined to the vicinity of the grain boundary, in region II the dislocations are spread into the grain interior, and in region III the dislocations rearrange to form walls. The evolution of substructure and the work-hardening behaviour are explained by considering both intragranular slip and its accommodation at the grain boundaries in these temperature regions. The activation energy and stress exponents for high-temperature deformation suggest that deformation is controlled by low-temperature recovery processes such as cross-slip at 700–800°C and high-temperature recovery processes such as dislocation climb at 825–900°C. © 1988 Taylor &amp; Francis Group, LLC.

Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties

Study on the substructure evolution and flow behaviour in type 316L stainless steel over the temperature range 21–900°C

Specimens were deformed to investigate the effect of strain, strain rate, and test temperature on microstructural evolution. The strain rates and temperatures investigated are 10** minus **5 to 10** minus **2 s** minus **1 and 400 degree to 540 degree C, respectively. Strain hardening occurs at lower strain rates irrespective of temperature. Strain hardening at lower strain rates and higher temperatures can be accounted for by grain growth. Strain hardening at lower temperature is caused partly by concomitant grain growth and partly by dislocation interactions. During deformation at higher strain rates, some strain softening associated with excessive cavitation is seen.