DoITPoMS

TLP Library

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

Brittle Fracture 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..
Crystallinity in Polymers 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.
Mechanical Testing of Metals 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 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.
Tribology and wear Tribology and wear
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.