BSc Materials Science and Engineering

Year of entry: 2024

Course unit details:
Deformation Mechanisms

Course unit fact file
Unit code MATS23502
Credit rating 10
Unit level Level 5
Teaching period(s) Semester 2
Offered by Department of Materials
Available as a free choice unit? No


This unit is concerned with the mechanisms of deformation and strengthening in crystalline and non-crystalline solids.


The unit aims to:

Provide an overview of the deformation mechanisms in crystalline and non-crystalline solids.

Provide a quantitative treatment of the strengthening mechanisms using simple physical models.

Provide a theoretical framework for the time dependent deformation of non-crystalline solids and how it is affected by microstructure.

Learning outcomes

A greater depth of the learning outcomes will be covered in the following sections:
  • Knowledge and understanding
  • Intellectual skills
  • Practical skills
  • Transferable skills and personal qualities


Teaching and learning methods

Lectures, group tutorials (problem sessions), recommended textbooks, web resources, past exam papers, electronic supporting information (Blackboard), peer-assisted study sessions (PASS).


Knowledge and understanding

Understand the origins of the strength of solids and its link to structure and microstructure.

Understand the physical mechanisms of plastic deformation in crystalline solids.

Know the concepts of slip, cross-slip, climb, diffusion and twinning.

Recognize the different defect types in crystalline solids and understand the role they play in plastic deformation.

Understand the concept of stored energy.

Understand the mechanisms that give rise to work hardening.

Know and understand how crystalline solids are strengthened by solid solution, grain size, and second phase particles.

Understand the effect of temperature on deformation mechanisms.

Understand the mechanisms responsible for viscoelasticity and how it depends on the molecular structure.

Understand the glass transition phenomenon, factors that affect it and how it can be determined. 

Intellectual skills

Show improved logical reasoning, problem solving and ability in applied mathematics.

The ability to use simple models to calculate the strength of crystalline solids. 

Practical skills

Use bend testing and microscopy to investigate the strengthening mechanism of light alloys

Carry out and interpret experiments to determine the glass transition temperature. 

Transferable skills and personal qualities

Convert word problems into equations and numerical answers.

Develop techniques for estimating the results from calculations.

Work effectively in a group to solve problems.

Compose simple technical reports on laboratory tests. 

Assessment methods

Method Weight
Written exam 70%
Written assignment (inc essay) 30%

Feedback methods

Written and verbal

Recommended reading

Introduction to dislocations” D. Hull and D.J. Bacon, Oxford : Butterworth Heinemann 4th ed, 2001 

“The plastic deformation of metals” R.W.K. Honeycombe, London : Edward Arnold 2nd ed. 1984 

“Mechanical metallurgy” George E. Dieter,: McGraw-Hill 2nd ed., New York ; London 1976.  

“Dislocations and plastic flow in crystals”, Alan Cottrell, Clarendon Press, Oxford 1953 

“Introduction to Polymer Science”, R.J. Young and P.A. Lovell, 2nd or 3rd Edition, CRC Press

Study hours

Scheduled activity hours
Lectures 22
Independent study hours
Independent study 78

Teaching staff

Staff member Role
Joao Quinta da Fonseca Unit coordinator

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