Programme And Module Handbook
Course Details in 2019/20 Session

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Module Title Environmental Degradation of Materials
SchoolMetallurgy and Materials
Department Metallurgy & Materials
Module Code 04 26593
Module Lead Dr Clive Ponton
Level Honours Level
Credits 10
Semester Semester 2
Pre-requisites Ferrous and Non-Ferrous Alloys and Applications - (04 22388)
Restrictions None
Contact Hours Guided independent study-78 hours
Lecture-22 hours
Total: 100 hours
Description This course relates to materials exposed to high temperatures. It can be divided into two parts:
Part A – High Temperature Corrosion of materials
Part B – High Temperature Mechanical behavior

In the treatment hereof a number of aspects will be addressed:
High temperature applications:
a) combustion engines and gas turbines
b) boiler materials (heater and steam pipes)
c) waste and bio mass incinerators
d) solid oxygen fuel cells
e) plasma-wall interactions

Materials for high temperature applications:
a) Fe and Ni based alloys (Laves phases)
b) superalloys
c) intermetallics (TiAl, NiAl etc)
d) ceramics
e) composites (metal matrix and ceramic matrix)
f) refractory materials and coatings
g) properties-temperature relations

Course contents:
Part A: High Temperature Corrosion
Introduction of high temperature oxidation
a) cases, applications
b) methods of investigation
c) accelerated test
d) lifetime prediction
Gas-solid interactions: oxidation, sulfidation, carburizing, nitriding
a) thermodynamics
b) construction of thermodynamic diagrams
c) calculation of activities in gaseous environments
d) oxidation, sulfidation, carburizing, nitriding
Mechanisms of oxidation
a) solid state diffusion, internal and external oxidation
b) oxidation kinetics, nucleation
c) Wagner theory
d) defect chemistry
Oxidation of pure metals and alloys
a) scale formation and
b) scale mechanical stability, stresses and adhesion
c) volatile species
d) selective oxidation
Reactions with mixed environments
a) sulfidation, carburizing, nitriding
b) watervapour effects
c) halogen effects
d) hot corrosion
e) metal dusting
f) erosion effects
Protective coatings
a) diffusion and overlay coatings
b) thermal barrier coatings
c) environmental barrier coatings

Part B: Mechanical Behaviour
Creep in crystalline solids (metals and ceramics)
a) creep testing
b) creep mechanisms
c) deformation mechanism maps
d) extrapolation procedures
e) creep resistant materials
f) creep fracture
High temperature fatigue (metal alloys)
a) testing
b) creep-fatigue interactions
c) effect of environment
Thermomechanical fatigue (metal alloys)
a) definitions
b) role of mechanical constraint
c) elastic / plastic shakedown
d) testing
e) TMF in super alloys: effects of phasing, crystal orientation, time, environment
f) lifetime prediction models
Thermal shock (ceramics)

Recommended Reading:
Text book on high temperature oxidation: N. Birks, G.M. Meijer and F.S. Petit, Introduction to the High Temperature Oxidation of Metals, 2nd edition, Cambridge University Press, 2006.
Text book on deformation and fracture mechanics of engineering materials: Richard Hertzberg, 4th edition, Wiley, 1996.
Learning Outcomes

By the end of the module students should be able to:

  • identify the different mechanisms by which creep can occur in crystalline solids and explain the principle and usage of deformation mechanism maps
  • perform extrapolations of creep rupture data
  • identify effects of temperature and environment for high-temperature fatigue
  • describe the conditions for which thermal/thermomechanical fatigue play a role
  • explain how isothermal and thermomechanical fatigue are tested and how lifetime is predicted
  • describe possible mechanisms of thermal/thermomechanical fatigue in high-temperature materials and identify the major affecting parameters
  • describe the phenomenon of thermal shock and explain the major parameters affecting this
  • understand gas-solid interactions; thermodynamics and reaction kinetis
  • understand methods of investigation for materials applied at high temperatures
  • give materials solutions for high temperature applications

(UK-Spec Learning Outcomes:- E1 & P1)

Assessment 26593-01 : Exam : Exam (Centrally Timetabled) - Written Unseen (100%)
Assessment Methods & Exceptions Exam
Other None
Reading List