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

Phd by thesis

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

/pdf/mechanical-behavior-of-materials-244bo22qlo.pdf

Mechanical Behavior of Materials

Biological materials: Structure and mechanical properties

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.

Recent developments in stainless steels

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.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1443&context=ameslab_manuscripts

Additively manufactured hierarchical stainless steels with high strength and ductility

In the present study, precipitation of sigma (σ) phase was investigated over the temperature range of 700-850 °C in undeformed and deformed (60% cold rolling) samples of 2507 super duplex stainless steel. The fraction of sigma phase formed as a result of the transformation α → σ + γ2 increases with increasing time and temperature. The increase in sigma phase leads to increase in yield strength and decrease in ductility. Preaging deformation leads to accelerated precipitation of sigma phase. The activation energy for sigma phase precipitation in deformed sample is found to be lower than that in undeformed sample.

Effect of Preaging Deformation on Aging Characteristics of 2507 Super Duplex Stainless Steel

Effect of processing on properties of thin walled calandria tubes for pressurised heavy water reactor

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.

A Process of Notch Wavy Rolling for Strengthening Metal Sheets

Superplastic behavior of a microduplex stainless steel (IN744) was studied by deforming specimens with initially elongated grains. As a result of deformation, grain growth and breaking up of elongated grains were noticed to occur concurrently. These microstructural instabilities result in strain hardening or strain softening, respectively. This then leads to nonuniqueness in the flow behavior. Some examples of nonuniqueness in stress-strain rate relation include the presence of: strength anisotropy, increase in strain rate sensitivity, constant stress level for varying grain size, and two distinct stress-strain rate curves over comparable test condition for the same initial microstructure. These have been explained by the concomitant microstructural changes and the influence of such changes on instantaneous flow stress. Emphasis is made on the need to eliminate microstructural instability in order to characterize the deformation phenomena under steady state.

Bhagwati Prasad Kashyap

Papers

Effect of Preaging Deformation on Aging Characteristics of 2507 Super Duplex Stainless Steel

Effect of processing on properties of thin walled calandria tubes for pressurised heavy water reactor

A Process of Notch Wavy Rolling for Strengthening Metal Sheets

Influence of nonsteady state behavior on superplastic deformation of a 25. 7 Cr-6. 6 Ni stainless steel

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