Overview

This module provides an introduction to materials science. The aim of the module is to link the properties of materials to their atomic structure and how their atoms are bonded together. It will then go on to show how this knowledge can be harnessed to design new materials by manipulating composition and processing conditions to tailor material properties to engineering need.

The theoretical basis for materials science will be taught through a series of lectures and tutorial sessions. These will cover the theory of the chemical bond, crystallography (how atoms are arranged in ordered materials) and the thermodynamics of materials. In order to allow students to quickly gain both a qualitative and quantitative understanding of phase equilibria the interpretation and use of phase diagrams will be used.

Students will be able to exercise their theoretical understanding of materials through a series of practical laboratory sessions. Predictions made using phase diagrams, combined with their new found knowledge of materials properties and crystal structure will be tested in the lab. Material samples will be prepared for examination using optical microscopes and have their properties measured. The students will then need analyse experimental results against their predictions to establish which materials are which amongst a number of candidates. This will not only provide a good introduction to materials science but it will also allow them to develop their practical lab and analytical skills.

This module provides an introduction and fundamental knowledge in the field of materials science.

Indicative content includes:

• What are materials? The states of matter will be introduced (gas, liquid and solid). The different classes of material will be presented in terms of their typical composition and characteristics. These will include metals, polymers, ceramics, glasses and composites.

• The atomic structure of materials (crystallography) The atomic structure of crystalline, amorphous and polymeric materials will be introduced and linked to the materials classes listed above. Crystalline materials will be described in some detail. The following aspects of crystallography will be introduced:

• The primitive lattices.
• The description of a crystal as a lattice and motif.
• Unit cell (primitive and full).
• Identifying planes and directions.
• Hexagonal lattices.
• Stacking sequences.
• Interstices.
• Typical defects.

• Prototypical crystal structures (e.g. BCC, FCC, HCP, fluorite, rock-salt, zinc-blende and diamond).

• Material properties. The meaning of basic material properties will be introduced: strength (yield and ultimate tensile strength), stiffness, Young's modulus, thermal expansion, specific heat capacity, thermal conductivity and electrical conductivity.

• The nature of the chemical bond: Covalent, ionic and metallic bonding will be described. The different materials classes will be related to bond types and properties such as conductivity, stiffness and theoretical strength will discussed in terms of bonding.

• Microstructure. The concept of microstructure will be introduced. The concept of phases, grains, grain boundaries, precipitates and porosity will be introduced. Typical microstructures will be presented and the effect of processing conditions described. This will included a discussion of equiaxed and columnar grain structures and how cooling rate and direction affect these. In addition the effect of forging on a cast microstructure will be shown.

• Chemical thermodynamics Binary phase diagrams will be described. The theoretical basis for phase diagrams will be introduced and their practical application will be demonstrated. They will be used to understand the cooling of typical materials from the melt. This will involve using phase diagrams to identify which phases are present, their composition and in what proportion they occur (through the use of the lever rule).

Assessment Strategy

-threshold -Equivalent to 40%. Uses key areas of theory or knowledge to meet the Learning Outcomes of the module. Is able to formulate an appropriate solution to accurately solve tasks and questions. Can identify individual aspects, but lacks an awareness of links between them and the wider contexts. Outputs can be understood, but lack structure and/or coherence.

-good -Equivalent to the range 60%-69%.Is able to analyse a task or problem to decide which aspects of theory and knowledge to apply. Solutions are of a workable quality, demonstrating understanding of underlying principles. Major themes can be linked appropriately but may not be able to extend this to individual aspects. Outputs are readily understood, with an appropriate structure but may lack sophistication.

-excellent -Equivalent to the range 70%+.Assemble critically evaluated, relevant areas of knowledge and theory to constuct professional-level solutions to tasks and questions presented. Is able to cross-link themes and aspects to draw considered conclusions. Presents outputs in a cohesive, accurate, and efficient manner.

Learning Outcomes

• Demonstrate the ability to work safely in a materials laboratory.

• Describe how atoms are arranged in the common states of matter and different materials classes.

• Discuss important materials properties including strength, stiffness and thermal expansion of a material and how these relate to atomic bonding.

• Understand that materials properties can be altered by adjusting composition and processing conditions.