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

Fine grains were developed in Mg-3Al-1Zn (AZ31) alloy by isothermal caliber rolling at five different temperatures in the range of 250-450°C. The samples of different grain sizes were deformed by constant strain rate and differential strain rate test techniques over the temperature range of 220-450 °C and strain rate range of 10-5 to 10-1 s-1. The effects of grain size, test temperature and strain rate on flow stSuperscSuperscript textript textress were analysed to develop the constitutive relationship for supSuperscript texterplastic deformation. The parameters of the constitutive relationship obtained from the constant strain rate tests and differential strain rate tests were used to find out the material constant A of the constitutive relationship.

Effect of Severe Caliber Rolling on Superplastic Properties of Mg-3Al-1Zn (AZ31) Alloy

Influence of prior thermal ageing on creep and low cycle fatigue behaviourof forged thick section 9cr-1mo ferritic steel at 793 k

As-cast AZ80 Mg alloy contains α-Mg, partially divorce eutectic of α and γ (Mg17Al12), fully divorce eutectic of α and γ, and lamellar eutectic of α and γ phases During homogenization, second phase (γ-Mg17Al12) gets dissolved can change the mechanical properties Therefore, the aim of the present work is to bring out the kinetics of dissolution of γ phase and evaluate its effect on mechanical properties Microstructure evolution during homogenization was investigated as a function of time for 05 to 100 h and at the temperatures of 400° and 439°C In as-cast state, this material was found to contain 70% α-Mg and 30% eutectic phase With increasing homogenization time, dissolution of lamellar eutectic occurs first which is followed by dissolution of fully divorce eutectic and partially divorce eutectic The dissolution kinetics of γ phase was analyzed based on the decrease in its volume fraction as a function of time The time exponent for dissolution was found to be 038 and the activation energy for the dissolution of γ phase was found to be 841 kJ/mol This dissolution of γ phase leads to decrease in hardness and tensile strength with increase in homogenization time

Phase Dissolution of γ‐Mg17Al12 during Homogenization of As‐Cast AZ80 Magnesium Alloy and Its Effect on Room Temperature Mechanical Properties

Zr-2.5 wt% Nb alloy sheet, obtained by unfolding and straightening a pressure tube, was further cold rolled upto 39% reduction in thickness to investigate the effect of cold working on the stress (σ)-strain rate (έ) behaviour over a strain rate range of ∼2 × 10−5 to 5 × 10−3 s−1 and a temperature range of 625 to 700 °C. Irrespective of the amount of rolling, the log σ vs log έ plots exhibit superplastic behaviour with strain rate sensitivity index, m, as high as 0.8, which decreases to 0.2 at higher strain rates. On the other hand, the activation energy for deformation, Q, increases from 171.1 kJ/mol for superplastic deformation to 249 kJ/mol in Region III. The tendency for improved superplasticity (m) is seen upon cold working by 22% or more at the test temperatures 675 and 700 °C.

Effect of prior cold rolling and test temperature on stress-strain rate behaviour of a Zr-2.5Nb alloy

1 Institute for Metals Superplasticity Problems RAS, Khalturin St. 39, 450001, Ufa, Russia 2Vikram Sarabhai Space Center, Trivandrum-695022, Kerala, India 3Indian Institute of Technology Bombay, Powai, Mumbai-400076, India Effects of equal-channel angular pressing (ECAP) at 325 oC to a strain, e~10, and post-ECAP annealing for 1 hr in the temperature range of 350–520 oC on structure of the cast and homogenized Al-Mg-Sc-Zr alloy 01570C were analyzed. It is found that annealing of ECAP processed material containing near homogeneous ultrafine-grained structure with ~1 μm grain size led to normal grain growth, accompanied by coarsening of Al3(Sc,Zr) dispersoids. As compared to the cast alloy, the coarsening of dispersoids in the deformed alloy started at lower temperature and occurred more intensely, and resulted in more rapid loss of their coherency with surrounding matrix.

/pdf/structure-and-annealing-behavior-of-an-al-mg-tm-alloy-1oy8iqe6i2.pdf

Bhagwati Prasad Kashyap

Papers

Effect of Severe Caliber Rolling on Superplastic Properties of Mg-3Al-1Zn (AZ31) Alloy

Influence of prior thermal ageing on creep and low cycle fatigue behaviourof forged thick section 9cr-1mo ferritic steel at 793 k

Phase Dissolution of γ‐Mg17Al12 during Homogenization of As‐Cast AZ80 Magnesium Alloy and Its Effect on Room Temperature Mechanical Properties

Effect of prior cold rolling and test temperature on stress-strain rate behaviour of a Zr-2.5Nb alloy

Structure and annealing behavior of an Al-Mg-TM alloy processed by equal channel angular pressing