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CME3097 : Materials degradation and Component Life

Semester 2 Credit Value: 15
ECTS Credits: 8.0


This module aims to:
•       Equip students to understand failure processes: creep, environmentally controlled fracture and fatigue that limit the life of engineering structures and to acquire the knowledge that will allow them to make estimates and predictions of the life and reliability of engineering structures.

•       Familiarise students with surface engineering principles underlying the phenomena of friction, wear and lubrication and the importance of their control in engineering practice, including the selection of materials for tribological applications (e.g. bearings), the application of surface engineering technologies and the recognition and solution of tribological problems.

•       Develop a general understanding of corrosion processes and corrosion control. To appreciate the role of chemical thermodynamics and kinetics in corrosion control and how this influences the selection of materials for engineering structures.

The failure and lifetime of engineering structures and commodity goods are often determined by the behaviour of the materials from which they are made. The behaviour of materials under service conditions that involve prolonged and/or repeated loading and exposure to chemical conditions is examined. Strategies to predict the lifetime of components are developed.

The module introduces the engineering science principles which underpin tribology, the study of friction, wear and lubrication. Premature failure of components due to wear is a driver for improved product design and the basis for tribological design is introduced. The course covers surface roughness, profilometry, contact mechanics and surface structures in order to provide an understanding of friction and wear mechanisms and how Lubrication and Surface Engineering can be used to ameliorate them.

Corrosion is a degradative process affecting many materials in day to day use. This module gives the theoretical background for the occurrence of corrosion and explains methods for controlling it, illustrating this using selected examples from industry. Aqueous corrosion will be the more common issue in engineering situations but brief discussion of dry oxidation will also be presented.

Outline Of Syllabus

Strength and deformation of metals and alloys at elevated temperature. Creep failure. Deformation maps, design against creep. Fatigue in engineering applications. Low cycle and high cycle fatigue. Manson-Coffin law, Miner’s rule, fatigue limits. Effect of stress concentrations. Surface contact fatigue. Fatigue crack growth rate. Reliability engineering, effect of distributions of applied stress and material properties.

Aqueous corrosion and corrosion control. General and localized corrosion, environmentally assisted failure to include corrosion fatigue, embrittlement and stress corrosion cracking of engineering materials with practical examples.

What is tribology? Surface shape and profile: asperities and true areas of contact. Contact mechanics: Hertz and Boussinesq stress fields and materials responses to contact stresses. The plasticity index. Friction processes: ways of controlling friction. Wear mechanisms: the Archard equation, 2 & 3-body wear; factors critically influencing wear rates. Ways of ameliorating wear. Surface engineering: techniques and examples of applications. Lubrication: boundary films hydrodynamic and solid lubricants. The behavior of bearings and bearing selection.

A brief overview of dry corrosion. Film growth mechanisms; oxidation kinetics; Pilling-Bedworth ratio. Oxidation-resistant materials and coatings. Case studies in oxidation.

Teaching Methods

Teaching Activities
Category Activity Number Length Student Hours Comment
Guided Independent StudyAssessment preparation and completion32:006:00Problem Solving Exercises
Guided Independent StudyAssessment preparation and completion12:302:30Exam
Guided Independent StudyAssessment preparation and completion118:0018:00Exam revision
Scheduled Learning And Teaching ActivitiesLecture361:0036:00N/A
Scheduled Learning And Teaching ActivitiesSmall group teaching121:0012:00Tutorials
Guided Independent StudyIndependent study175:3075:30Review lecture notes and recommended texts as appropriate
Teaching Rationale And Relationship

The lectures are designed to assist the student in the acquisition of a knowledge base that will facilitate understanding of creep, fatigue, wear and corrosion of materials.

Tutorial exercises will enable students to practise analysis of systems and predict failures.

Private study will strengthen their knowledge base and enable students to tackle the calculations and problems with greater ease.

Assessment Methods

The format of resits will be determined by the Board of Examiners

Description Length Semester When Set Percentage Comment
Written Examination1502A85N/A
Exam Pairings
Module Code Module Title Semester Comment
CME8032Lifetime Prediction & Design for Reliability1N/A
Other Assessment
Description Semester When Set Percentage Comment
Prob solv exercises2M153 assessed problem solving exercises as assigned (5% each)
Assessment Rationale And Relationship

The subject has a significant ‘academic’ content, including quantitative analysis of creep, fatigue, corrosion rates etc. and so is well suited to assessment by examination.

The tutorial exercises enable students to put into practice what they have learnt in class to assess the behaviour and life of components.

Reading Lists