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.

Brittle Fracture

What determines when a material will break, and whether failure will be catastrophic or more gradual. Cracking is controlled by the energy changes that occur - it is not the stress at the crack tip that is important..

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.

Crystallinity in Polymers

An understanding of polymer crystallinity is important because the mechanical properties of crystalline polymers are different from those of amorphous polymers. Polymer crystals are much stiffer and stronger than amorphous regions of polymer.

Diffraction and Imaging

A brief summary of diffraction and imaging using an optical system.

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.

The Jominy End Quench Test

Discusses the aims, method and use of results of a test for the hardenability of steel.

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.

Phase Diagrams and Solidification

Phase diagrams are a useful tool in metallurgy and other branches of materials science. They show the mixture of phases present in thermodynamic equilibrium. This teaching and learning package looks at the theory behind phase diagrams, and ways of constructing them, before running through an experimental procedure, and presenting the results which can be obtained.

Introduction To Photoelasticity

This tutorial is based on lab work within the Department of Materials Science and Metallurgy at the University of Cambridge. The tutorial provides an introduction to the topic of photoelasticity and preparation for lab work. Photographs illustrate many features of birefringence in polymers under polarised light.

Superelasticity and Shape Memory Alloys

This teaching and learning package (TLP) introduces the phenomena of superelasticity and the shape memory effect.

Thermal Expansion and the Bi-material Strip

This teaching and learning package (TLP) is based on lab work in the Department of Materials Science and Metallurgy at the University of Cambridge. The TLP provides an introduction to the topic of thermal expansion, and its application, together with the different stiffness of materials, in the bi-material strip. The TLP leads you through experiments to measure Youngs Modulus from the deflection of a cantilever beam, and to estimate the boiling temperature of nitrogen and the expansivity of a polycarbonate material from the curvature of a bi-material strip immersed in liquid nitrogen.

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.

X-ray Diffraction Techniques

This teaching & learning package provides an introduction to X-ray diffraction. It describes the main crystallographic information that can be obtained and experimental methods most commonly used.