Last modified: 28 Jun 2018 10:27
The course focuses, initially, on the major groups of solid materials – metals, ceramics, polymers, and provides an introduction to materials selection. Strengthening mechanisms in these systems and the relationship between microstructure and mechanical properties are highlighted. The main failure and degradation processes of materials in service, fracture, fatigue, creep and corrosion, are considered. The major welding and adhesive bonding processes are introduced, and structural integrity of welded joints is examined. Finally, the course gives a comprehensive introduction to composite materials and motivation for their use in current structural applications. Manufacturing of different types of composites is reviewed.
|Session||First Sub Session||Credit Points||15 credits (7.5 ECTS credits)|
1. Introduction to Materials Selection. Selection strategies; Translation, screening and documentation; Ranking using material indices. CES EduPack materials selector software.
2. Deformation and Strengthening Mechanisms. Dislocations and materials classes, dislocation motion in metals; Strategies for strengthening metals and alloys, grain size reduction, solid-solutions strengthening (alloying), precipitation strengthening (age hardening), cold working (strain hardening); Heat treatment, recovery, recrystallization and grain growth; Deformation mechanisms for ceramic materials; Brittle crosslinked and network polymers, semicrystalline (plastic) polymers, elastomers.
3. Failure and Degradation. Mechanical failure, ductile and brittle fracture behaviour in metals, ceramics and polymers; Crack propagation: linear-elastic fracture mechanics, strain energy release rate and fracture toughness, elastic-plastic fracture mechanics, crack opening displacement, design against crack growth; Impact fracture testing; Fatigue behaviour: S-N curves, endurance, cumulative damage, fatigue crack growth, Paris Law, improving fatigue life; Creep and viscoelastic behaviour: primary, secondary and tertiary creep, creep rupture testing, Larson-Miller parameter, Master Creep Curves, stress relaxation, viscoelasticity of plastics, isometric and isochronous curves; Corrosion of metals: forms of corrosion, electrochemical corrosion, Standard Hydrogen Electrode, standard emf Series, Nernst equation, corrosion rates, the galvanic Series, corrosion prevention.
4. Joining. Welding, brazing and soldering, fusion welding processes and parameters; heat-affected zone (HAZ) in welding, distortion and cracking in welds, structural integrity of welded joints; Adhesive bonding.
5. Basic Concepts and Characteristics of Composite Materials. Advantages and limitations of composites; Applications of composites; Types and classification of composites; Composites as anisotropic materials; Constituent materials and their properties, overview of different types of reinforcements and matrices; Reinforcement-matrix interface. Manufacturing of fibrous composites: Polymer matrix composites, metal matrix composites, ceramic matrix composites.
6. Strength and Failure of Composites. Determination of stiffness properties of unidirectional fibre-reinforced composite material; Failure of unidirectional fibre-reinforced composite material under different types of loading; Damage mechanisms, damage accumulation; Prediction of strength.
Materials Selection in Design: Students will undertake a materials selection exercise using the CES EduPack materials selection software.
Information on contact teaching time is available from the course guide.
1st Attempt: 1 three-hour written examination paper (90%), and in-course assessment (10%). Resit: 1 three-hour written examination (90%), and continuous assessment mark from the 1st attempt (10%)
The continuous assessment will be based on the keeping of a lab logbook and this serves as both formative and summative assessment.