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

Mechanical properties of nanocrystalline materials

http://www.uniroma2.it/didattica/tbs2/deposito/Manufacture,_characterisation_and_application_of_cellular_metals_and_metal_foams.pdf

Manufacture, characterisation and application of cellular metals and metal foams

There have been a number of review papers on layered silicate and carbon nanotube reinforced polymer nanocomposites, in which the fillers have high aspect ratios. Particulate–polymer nanocomposites containing fillers with small aspect ratios are also an important class of polymer composites. However, they have been apparently overlooked. Thus, in this paper, detailed discussions on the effects of particle size, particle/matrix interface adhesion and particle loading on the stiffness, strength and toughness of such particulate–polymer composites are reviewed. To develop high performance particulate composites, it is necessary to have some basic understanding of the stiffening, strengthening and toughening mechanisms of these composites. A critical evaluation of published experimental results in comparison with theoretical models is given.

/pdf/effects-of-particle-size-particle-matrix-interface-adhesion-yv055zq7xi.pdf

Effects of particle size, particle/matrix interface adhesion and particle loading on mechanical properties of particulate–polymer composites

Below 1000°C the oxidation of nickel cannot be controlled by the diffusion of ions through the bulk crystal lattice of the pure oxide, because the measured oxidation rates are several orders of magnitude faster than would be predicted on this basis. Short-circuit diffusion through oxide grain boundaries or dislocations has usually been held responsible, but there has hitherto been no proper quantitative confirmation of this mechanism. We report measurements of the oxide scale thickness and oxide grain size as a function of time during the oxidation of high-purity nickel in the temperature range 500–800°C. All the oxidation experiments were carried out in pure oxygen at a pressure of one atmosphere. The measured parabolic oxidation rate constants have been compared with those calculated from grain boundary diffusion data obtained in our previous work, using a grain boundary diffusion model for the oxidation process. The quantitative agreement between measured and calculated oxidation rates shows c...

A quantitative demonstration of the grain boundary diffusion mechanism for the oxidation of metals

A metallography solution for grain boundary diffusion estimation in polycrystals

The shape changes in a (111)[123] single crystal deformed in plane strain compression have been analysed. T.E.M. studies revealed that high angle grain boundaries are produced during deformation. Identical boundaries arise also by thermal recovery indicating that similar structural processes occur at high strains during both dynamic and thermal recovery.

Structural Aspects of Dynamic Recovery at Large Plastic Strains

Crack Shape Study in a Brittle Non-bonded Particular Composite

At large plastic strains consideration must be given not only to the descriptions of work hardening and texture evolution but also to the process of damage accumulation and the documentation of the various modes of failure which may terminate the plastic history. In this presentation consideration is given first to documenting the various modes of failure and their dependence on stress state. It is then shown that damage accumulation can be studied in a quantitative manner by using model systems in conjunction with FEM calculations. Finally consideration is given to complex forming processes such as ironing to show how studies of damage initiation and accumulation relate to practical engineering problems

https://hal.archives-ouvertes.fr/docs/00/25/22/19/PDF/ajp-jp4199303C799.pdf

Damage and failure processes in structural materials

The production of drawn and ironed (D&I) beverage cans represents an important example of process optimisation. The aluminium alloy 3004 H19 is widely used for the can body, since it has a good combination of formability and strength and results in very little earing after deep drawing. These desirable properties are achieved by exercising careful control of the rolling schedule of the can stock sheet. During the ironing stage the wall thickness is reduced by a factor of about three, and these large strains determine the resulting texture in the can wall. Large shear strains are also present and these can vary through the wall thickness. The present work deals with the deformation and texture evolution when ironing strips of 3004 aluminium. The strip material was in either a cold rolled or an annealed condition. The texture on each surface of the ironed strips, as well as at the mid-plane, was determined experimentally. The experimental results were then compared with the results from a computer program which was capable of predicting the texture evolution.

/pdf/deformation-and-texture-evolution-of-a-3004-aluminium-alloy-3eznrda8rz.pdf

J.D. Embury

Papers

A metallography solution for grain boundary diffusion estimation in polycrystals

Structural Aspects of Dynamic Recovery at Large Plastic Strains

Crack Shape Study in a Brittle Non-bonded Particular Composite

Damage and failure processes in structural materials

Deformation and Texture Evolution of a 3004 Aluminium Alloy During Ironing