Dissemination of IT for the Promotion of Materials Science (DoITPoMS)

DoITPoMS TLP Library

TLP Library

Teaching and learning packages (TLPs) are self-contained, interactive resources, each focusing on one area of Materials Science.

TLPs containing HTML5 animations/simulations are labelled with the tag . We have found that often the HTML5 animations render better in Microsoft Edge, so if your favourite browser does not work very well with them, please try an alternative.

Analysis of Deformation Processes

This TLP builds upon the introduction to yield criteria covered in the Stress analysis and Mohr's circle TLP and introduces a range of methods commonly used to study metal forming processes.

Introduction To Anisotropy

It is common in basic analysis to treat bulk materials as isotropic - their properties are independent of the direction in which they are measured. However the atomic scale structure can result in properties that vary with direction. This teaching and learning package (TLP) looks into typical examples of such anisotropy and gives a brief mathematical look into modelling the behaviour.

Casting

This TLP introduces a number of important processes through which metallic items can be fabricated from molten metal. As well as detailing the practical aspects of these manufacturing processes, attention is given to the important parameters which determine the microstructure of the finished items.

Creep Deformation of Metals

Creep is a major concern, since it can cause materials to progressively deform, and possibly to fail, under applied stresses below their yield stress. This is particularly likely at elevated temperatures. In this package, the main mechanisms of creep are outlined and some analytical expressions presented that are used to represent its progression. Testing procedures are described, covering both simple uniaxial loading and more complex test geometries. It is shown how creep characteristics can be inferred from the outcome of such tests, requiring in some cases numerical (finite element) modelling of the process. Information is also presented about the design of highly creep-resistant materials.

Introduction To Deformation Processes

This teaching and learning package covers the fundamentals of metal forming processes.

Diffusion

An introduction to the mechanisms and driving forces of diffusion, and some of the processes in which it is observed.

Dislocation Energetics

This teaching and learning package (TLP) uses an atomistic model of the misfit energy to predict dislocation width and Peierls stress.

Introduction To Dislocations

Dislocations are crucially important in determining the mechanical behaviour of materials. This teaching and learning package provides an introduction to dislocations and their motion through a crystal. A 'bubble raft' model is used to demonstrate some of the features of dislocations and other lattice defects. Some methods for observing real dislocations in materials are examined.

Electromigration

Electromigration is an ever-increasing problem as integrated circuits are pushed towards further miniaturization. The theory of the phenomenon is explained, including electromigration-induced failure and how it has been and can be minimized.

Mechanical Testing of Metals

This teaching and learning package (TLP) introduces the basic mechanics involved in mechanical testing of metals, first outlining the meaning of deviatoric and hydrostatic stresses and strains, followed by definitions of true and nominal values and then covering the idea of constitutive laws that characterise the development of plastic deformation. The issues involved in carrying out conventional uniaxial (tensile and compressive) tests, and interpreting experimental outcomes, are then described. Finally, hardness testing is explained, followed by the development of a related technique involving indentation testing that allows full stress-strain curves to be obtained. All of the analyses are based on a continuum treatment of plastic deformation, with extensive numerical modelling, using the Finite Element Method (FEM).

Mechanisms of Plasticity

This TLP should provide some insights into the plasticity of crystals. It covers some of the important concepts in single-crystals such as Frank-Read source, Lomer locks, climb and cross-slip, and their roles in forest hardening. In addition, grain boundary hardening in poly-crystals is also explained.

Slip in Single Crystals

This teaching and learning package explains how plastic deformation of materials occurs through the mechanism of slip. Slip involves dislocation glide on particular slip planes. The geometry of slip is explained, and electron microscopy techniques are used to show slip occurring in single crystals of cadmium.

Solidification of Alloys

This teaching and learning package (TLP) is an introduction to how solute affects the solidification of metallic alloys.

Stress Analysis and Mohr's Circle

This teaching and learning package provides an introduction to the theory of metal forming. It discusses how stress and strain can be presented as tensors, and ways of identifying the principal stresses. Suitable yield criteria to treat metals and non-metals are also presented.

Tribology - the friction and wear of materials

Consideration of the behaviour of surfaces in contact with one another leads to the subject of tribology ? the study of the friction, lubrication and wear of materials.