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

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

A simple instability condition is applied to delineate the regions of unstable metal flow in the processing map utilising flow stress data for AFNOR 7020 aluminium alloy, which was fitted in a constitutive equation Unstable regions identified from the simple instability condition at different strain levels were superimposed in the processing map This phenomenon takes into account the dependence of strain rate sensitivity and strain hardening effect on plastic instability during hot deformation of the material The processing map has been developed and validated by comparing microstructural observations of deformed compression specimens

Development and validation of a processing map for AFNOR 7020 aluminium alloy

An AA6082 alloy was subjected to eight passes of equal channel angular pressing at 100 °C, resulting in an ultrafine grain size of 0.2 to 0.4 μm. The tensile deformation behavior of the material was studied over the temperature range of 100 °C to 350 °C and strain rate range of 10−4 to 10−1 s−1. The evolution of microstructure under tensile deformation was investigated by analyzing both the deformation relief on the specimen surface and the dislocation structure. While extensive microshear banding was found at the lower temperatures of 100 °C to 150 °C, deformation at higher temperatures was characterized by cooperative grain boundary sliding and the development of a bimodal microstructure. Dislocation glide was identified as the main deformation mechanism within coarse grains, whereas no dislocation activity was apparent in the ultrafine grains.

Plastic Flow Properties and Microstructural Evolution in an Ultrafine-Grained Al-Mg-Si Alloy at Elevated Temperatures

A microduplex stainless steel (25.7 wt% Cr-6.6 wt% Ni) was investigated to examine grain growth during static annealing and superplastic deformation at 1000° C. The grain size at a constant strain rate of 1×10−4 sec−1 increases according to d∼8t
0.49 where d is the grain size and t is the time (in min) involved in deformation. Under the present test condition, the contribution of both static (time, t
S) and dynamic (strain, e) annealing appear to be significant and can be expressed by d∞
0.19e0.29. While the exponent of the first term is constant, the exponent of the second term may depend on the strain rate. Strain rate sensitivities were evaluated from differential strain rate tests for different initial grain sizes. Both strain rate sensitivity and grain size were noticed to increase with deformation.

Bhagwati Prasad Kashyap

Papers

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

Development and validation of a processing map for AFNOR 7020 aluminium alloy

Plastic Flow Properties and Microstructural Evolution in an Ultrafine-Grained Al-Mg-Si Alloy at Elevated Temperatures

Investigation on grain growth and strain rate sensitivity of a superplastic microduplex steel at 1000°C

Analysis of first order kinetics for tertiary creep in AISI 304 stainless steel