What is materials science?
The study of the relationships between structures and properties of materials as well as research into the development of new materials.
What is materials engineering?
The creation of products from existing materials and the development of materials processing techniques.
What were the three major material ages?
Stone, bronze, and iron.
How are the properties of materials determined?
By their structures
What are the 4 levels of structure?
- Atomic structure
- Atomic arrangement
- Microstructure
- Macrostructure
What is a property?
A material’s response to a stimulus and is independent of size and shape.
What are the relationships between processing, structure, and properties?
Structure is dependent on processing. Properties are dependent on structure.
What are the three classifications of materials?
- Metals
- Plastics/polymers
- Ceramics
What are the properties of metals?
- Strong, ductile
- High thermal and electrical conductivity due to non-localized electrons
- Opaque, reflective
What are the properties of polymers/plastics?
- Compounds of non-metallic elements
- Soft, ductile, low strength, low density
- Low thermal and electrical conductivity
- Opaque, translucent, or transparent
What are the properties of ceramics?
- Compounds of metallic and non-metallic elements
- Hard, brittle
- Low thermal and electrical conductivities
- Opaque, translucent, or transparent
List the materials in order of conductivity: ceramics, metals, polymers, semiconductors.
- Metals
- Semiconductors
- Ceramics
- Polymers
List the order of procedure in materials selection.
- Application
- Properties
- Materials
- Processes
What are the six material property types?
- Mechanical
- Electrical
- Thermal
- Magnetic
- Optical
- Deteriorative
What do mechanical properties relate to?
Deformations
How does carbon content affect the hardness of a common steel?
Increasing carbon content increases the hardness of steel.
What do electrical properties relate to?
Electrical resistivity
What are three ways to increase resistivity?
- Increasing temperature (atoms excite and make it harder for electrons to travel)
- Increase impurity (impurities act like barriers so electrons get slowed moving around)
- Deform (disrupts the structure changing the path electrons take)
What do thermal properties relate to?
Thermal conductivity
What is one way to decrease thermal conductivity?
Increase impurity
Why are highly porous materials poor conductors of heat?
Porous materials have significant void spaces or gaps that hold air, which is a poor conductor of heat.
What do magnetic properties relate to?
Magnetic storage (the ability to store magnetic charges) and magnetic permeability (the ability to magnetize under an applied magnetic field).
What do optical properties relate to?
Light transmittance
What is the difference between single-crystal and polycrystalline structures?
Single-crystal structures are composed of atoms aligned in one direction.
Polycrystalline structures are composed of grains, where atoms in each grain are aligned in one direction.
