What are Materials Classed as?
- Metals
- Polymers
- Ceramics
- Composites
What are the Mechanical Properties of Materials?
- Strength
- Hardness
- Elasticity
- Stiffness
- Plasticity
- Malleability
- Ductility
- Faitugue
- Notch Toughness
what is Strength?
Withstand applied lads without failure
What is Hardness?
Resist scratching, abrasion or indentation
what is Elasticity
Return to its original shape and dimensions after being subjected to a load.
what is Stiffness
Resit elastic deformation under load
What is plasticity
Undergo some degree of permanent deformation without rupture
What is Malleability
Be hammaered or rolled into thin sheets
What is Ductility
drawn out into a thin wiere
what is fatigue
The tendency of a material to break when subjected to repeated cyclic loading where the induced stress is well under the elastic limit
What is Notch Toughness
A measure of the amount of energy required to cause failure
What the 3 Types of Magnetism
- Diamagnetic : Ionic and molecular materials
- Paramagnetic: Materials with a single valance election
- Ferromagnetic: Large amounts of unpaired elections can become permanent magnets
List the Physical Properties of Materials
- Density : P = m/v - Porosity
- Moisture content
List Properties of Metals
- High Electrical Conductivity
- High Thermal Conductivity
- Ductile
- Tough
- Strong (Strength)
- Stiff
What are alloys and why are they used?
Alloys are a combination of elements / metals which are created to achieve desired properties such as Hardness
What are Ferrous Metals / Alloys? - Give Examples
Metal Alloys that contain greather than 50% iron content. E.g
- Plain Carbon Steels
- Alloy Steels
- Cast Irons
What are Non- Ferrious Alloys? - Give Examples
Metals alloys that contain less than 50% Iron content e.g.
- Light alloys of Aluminium, Magnesium, Titanium, Zinc
- Heavy Alloys of Copper, Lead, Nickel
- Precious Metals - Gold, Silver, Platnium
- Heating resting metals - Molybdenum, Tungsten
List the properties of Copper
- Excellent Electrical conductivity (used primarly in wiring and motors
- Ductile
- Corrosion Resistence (Used in roofing / gutters, cookware)
List properties of Aluminium
- Corrosion resistant and light weight (Foil, Cans, CD, Kitchenware)
List the Propeties of Brass
Alloy of Copper and Zinc (Mostly Copper, known as a copper alloy)
- Bright Gold like apperance (Decorations)\
- Used where low friction is required (Locks, Door Knobs, Bearings)
- Brass Instruments - Mallable with Acoutsitc properties (softer the metal, warmer the sound)
List the Properties of Bronze
Composed of Tin and Copper
B20 Bronze = 20% Tin 80% Copper
Tougher B8 Bronze = 8% Tin 92%
Copper Ideal for machining into bronze bearings and bushings
- Malleable
- Low metal on metal friction Used for Sculptures, Instruments and Medals
- Corrosion resistant
List the Properties of Aluminium Bronze
Composed of Copper / Aluminium -High shock resistance
- Corrosion resistant
- High Strength / Toughness
- Good Casting and welding characteristics (Used in machinary tools)
What are the different types of Bonds?
Primary: Ionic, Covalent, Metallic
Secondary: Van Der Waals, Hydrogen
What are Allotopes?
Allotropes are different forms of a material due to modified bonding.
