Material Science Course

• Material science focuses on understanding the relationship between the structure, properties, processing, and performance of materials.
• This course introduces materials, crystal structures of solids, and the use of phase diagrams in material systems.
• It also covers the relationship between crystal structure and the properties of metallic materials, heat treatment of steels, and types of polymers, ceramics, glasses, and semiconducting materials and their applications.
• The material science course consists of eight chapters.

Course outline

• Chapter 1: Introduction to Material Science
• Chapter 2: Atomic structure and Atomic bonding
• Chapter 3: Crystal Structure
• Chapter 4: Crystal imperfection and atom movement
• Chapter 5: Diffusion
• Chapter 6: Mechanical Testing and Evolution
• Chapter 7: Equilibrium Phase Diagrams
• Chapter 8: Iron-Iron Carbide Phase Diagram

Evaluation

• Evaluation:
• Quizzes are worth 10 marks.
• Attendance is worth 10 marks.
• Project is worth 20 marks.
• Midterm is worth 20 marks.
• Final exams are worth 40 marks, for a total of 100 marks.

Material science

• The knowledge obtained includes the relationships between the internal structure and properties, including the processing of materials.
• Materials engineering involves designing or engineering the structure of a material to produce specific properties based on structure-property correlations.

Structure and subatomic structure

• A material's structure relates to the arrangement of its internal components.
• Subatomic structure concerns the electrons within individual atoms and their interactions with nuclei.

Microstructure and macrostructure

• Microstructure is observed using a microscope that involves larger groups of atoms normally agglomerated in grains.
• Macrostructure shows the structural elements that can be viewed.

Properties

• Solid material properties are grouped into six categories: mechanical, electrical, thermal, magnetic, optical, and deteriorative.
• Mechanical properties relate to deformation under load, like elastic modulus and yield strength.
• Thermal properties include thermal conductivity and heat capacity.
• Magnetic properties concern a material's response to a magnetic field.
• Optical properties relate to refraction and reflectivity of light.
• Deteriorative characteristics involve the chemical reactivity of materials.

Connection of Material science to engineering

• The field is the investigation of the relationships among processing, structure, properties, and performance of materials to the design and creation of new materials.
• Examples - the three aluminum oxides vary in light transmittance depending on processing and structure.

Classification of materials

• Materials are grouped into three groups based on chemical properties and atomic arrangement: metals, polymers, and ceramics.
• Additional material classifications are composites, semiconductors, and biomaterials.

Metals

• Metals are composed of metal objects or non-metals mixed with valence electrons, held together by the attraction of positive charges to the "electron sea".
• Metals conduct heating and electricity well, impermeable to light and are strong and tough.
• Ferrous and Nonferrous Metals and Alloys are examples of metal.

Polymers

• Polymers consist of plastic and are mostly organic containing carbon and molecules in a chain.
• Polymers have good electrical insulation and some have heat insulation, are flexible and lightweight, and also have low strength.
• Plastic, Rubber, PVC, and Epoxy are examples of polymers.

Ceramics

• Ceramics are made of metal and non-metal.
• They are usually oxides, carbides, and nitrides, insulating to heat and electricity, high temperature resistant and they are more durable than metals and polymers in toxic environments; strong but fragile
• Glass, Brick, Alumina, SiN, SiC, Zirconia, and Clay are examples of ceramics.

Composite

• Composite materials combine two or more main groups that should not dissolve into each other.
• Properties of composites derive from a combination of materials, such as fiberglass that mixes glass fibers with polymers or steel fibers and reinforced concrete for strength and longevity.

How materials rates against other materials

• Hardness: Polymer < Metals < Ceramic
• Toughness: Ceramic < Metals < Polymer
• Melting point: Polymer < Metals < Ceramic
• Heat conduction: Ceramic < Polymer < Metals
• Electrical conductivity: Ceramic < Polymer < Metals

Advanced material

• Materials used in high-tech applications are often called advanced materials.
• It covers metal, ceramics and polymers which are normally expensive.
• Specific type of advanced material includes semiconductors, biomaterials, smart materials and nano-materials.

Semiconductors

• A semiconductor's electrical properties lie in the middle, between that of conductors/insulators, such as pure silicon which is created in different ways
• The conductivity of semiconductors rises as temperature rises, better than metal conductivity.
• Silicon chips and microelectronic devices can be made using this process.

Application of semiconductors

• Application of semiconductors:
• Silicon wafers used in photovoltaic cells converts light into electrical energy
• Semiconductor memories are semiconductor-based integrated circuits for data storage.
• Transistors are another semiconductor device that amplifies and switches electronic signals.

Smart Material

• Sensors and actuators are used to detect changes in light intensity, temperature, color, or electrical response to changes in the environment.
• Shape-memory alloys, which return to a pre-deformed shape when heated, and may be referred to as memory metal are a type of smart material.

Superconductors

• The electrical resistivity of a metallic conductor decreases as the temperature decreases.
• Resistance drops abruptly to zero in a superconductor at a critical temperature.
• Electric current flowing in a loop of superconducting wire can persist with no power source.
• Superconductors, using the Meissner effect, trains float on magnets by eradicating friction on its track.

Biomaterials

• Biomaterials is a material with a therapeutic role as it can be implanted or integrated in the human body to fix a human organ.
• Examples: prosthetics, artificial bones, implants, prostheses, and hip joints.

Modern material needs

• Lighter materials for transportation vehicles will save weight
• Materials with increased heat tolerance in the engine.
• Materials made for solar cells
• Lightweight batteries with high storage densities.

Testing

• There are destructive and non-destructive methods to testing materials.
• Tests that are destructive include testing in areas such as, tension, compression, hardness, impact, bending, fatigue, creep, wear, and torsion.
• Non-destructive methods include areas such as visual, liquid penetrant, ultrasonic, radiographic, magnetic particle, and eddy current inspections.