Bhagwati Prasad Kashyap

Bio: Bhagwati Prasad Kashyap is an academic researcher from Indian Institute of Technology Bombay. The author has contributed to research in topics: Strain rate & Superplasticity. The author has an hindex of 31, co-authored 148 publications receiving 2796 citations. Previous affiliations of Bhagwati Prasad Kashyap include University of Manitoba & University of California, Davis.

The effect of grain size and composition on the fracture toughness of Ti–Al–Nb alloys undergoing stress-induced martensitic transformation

Abstract: The effect of grain size and composition on the fracture toughness of Ti–Al–Nb alloys in β solution-treated condition was investigated The fracture toughness of the alloys was found to increase with an increase in grain size initially, reach a maximum and subsequently decrease with further increase in grain size This trend was attributed primarily to the effect of grain size on the enhancement of fracture toughness due to stress-induced martensitic transformation (SIMT) at the crack tip, which in turn can be related to the effect of grain size on trigger stress for SIMT Alloys containing higher Al and Nb showed a higher toughness for the same grain size, which was also explained in terms of effect of composition on the trigger stress

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

Abstract: 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.

Influence of Particle Arrangement on Coarsening during Sintering of Three Spherical Particles

Abstract: Three-dimensional numerical simulation was performed to show that coarsening and grain growth was affected by particle arrangement in sintering of identical spheres. In the sintering of a row of three spheres the center particle with the coordination number of 2 coarsened, while particles on both sides with coordination number of 1 shrank and disappeared. The particles on both sides disappeared in a shorter time with increasing ratio of grain boundary energy γgb to surface energy γS. A new bond between two particles on both sides was created during sintering of three spheres with bond angle of 70°. This particle rearrangement changed the coordination number, and retarded the coarsening.

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Mechanical Behavior of Materials

Abstract: A balanced mechanics-materials approach and coverage of the latest developments in biomaterials and electronic materials, the new edition of this popular text is the most thorough and modern book available for upper-level undergraduate courses on the mechanical behavior of materials To ensure that the student gains a thorough understanding the authors present the fundamental mechanisms that operate at micro- and nano-meter level across a wide-range of materials, in a way that is mathematically simple and requires no extensive knowledge of materials This integrated approach provides a conceptual presentation that shows how the microstructure of a material controls its mechanical behavior, and this is reinforced through extensive use of micrographs and illustrations New worked examples and exercises help the student test their understanding Further resources for this title, including lecture slides of select illustrations and solutions for exercises, are available online at wwwcambridgeorg/97800521866758

Recent developments in stainless steels

Abstract: This article presents an overview of the developments in stainless steels made since the 1990s. Some of the new applications that involve the use of stainless steel are also introduced. A brief introduction to the various classes of stainless steels, their precipitate phases and the status quo of their production around the globe is given first. The advances in a variety of subject areas that have been made recently will then be presented. These recent advances include (1) new findings on the various precipitate phases (the new J phase, new orientation relationships, new phase diagram for the Fe–Cr system, etc.); (2) new suggestions for the prevention/mitigation of the different problems and new methods for their detection/measurement and (3) new techniques for surface/bulk property enhancement (such as laser shot peening, grain boundary engineering and grain refinement). Recent developments in topics like phase prediction, stacking fault energy, superplasticity, metadynamic recrystallisation and the calculation of mechanical properties are introduced, too. In the end of this article, several new applications that involve the use of stainless steels are presented. Some of these are the use of austenitic stainless steels for signature authentication (magnetic recording), the utilisation of the cryogenic magnetic transition of the sigma phase for hot spot detection (the Sigmaplugs), the new Pt-enhanced radiopaque stainless steel (PERSS) coronary stents and stainless steel stents that may be used for magnetic drug targeting. Besides recent developments in conventional stainless steels, those in the high-nitrogen, low-Ni (or Ni-free) varieties are also introduced. These recent developments include new methods for attaining very high nitrogen contents, new guidelines for alloy design, the merits/demerits associated with high nitrogen contents, etc.

Additively manufactured hierarchical stainless steels with high strength and ductility

Abstract: Many traditional approaches for strengthening steels typically come at the expense of useful ductility, a dilemma known as strength-ductility trade-off. New metallurgical processing might offer the possibility of overcoming this. Here we report that austenitic 316L stainless steels additively manufactured via a laser powder-bed-fusion technique exhibit a combination of yield strength and tensile ductility that surpasses that of conventional 316L steels. High strength is attributed to solidification-enabled cellular structures, low-angle grain boundaries, and dislocations formed during manufacturing, while high uniform elongation correlates to a steady and progressive work-hardening mechanism regulated by a hierarchically heterogeneous microstructure, with length scales spanning nearly six orders of magnitude. In addition, solute segregation along cellular walls and low-angle grain boundaries can enhance dislocation pinning and promote twinning. This work demonstrates the potential of additive manufacturing to create alloys with unique microstructures and high performance for structural applications.