1.1 materials and their properties

• what are the 6 material properties

  Strength, ductility, malleability, hardness, stiffness, toughness and brittleness
• what is strength

  the ability of a material to withstand a force applied to it
• Tensile strength:

  the ability to resist a pulling force
• Compressive strength:

  the ability to resist a squeezing force
• Torsional strength :

  The ability to resist a twisting force
• Yeild strength :

  The amount of stress needed to start permanently deforming a material
• Ultimate tensile strength :

  The amount of stress at which the material fails
• Stress = force/cross-sectional area
• Ductility:

  The amount that a material can be deformed
• strain = change in length/original length
• Malleability:

  The ability of a material to be deformed without rupturing
• Hardness:

  The ability of a material to resist wear and abrasion
• Toughness:

  the ability of a material to withstand an impact without breaking
• Brittleness:

  the potential for a material to shatter when it experiences impact
• Stiffness:

  the ability of a material to resist bending
• Young's modulus :

  the ratio of stress to strain in a material, showing how stiff it is
• Stress = Force/Cross-sectional area
• Young's Modulus =stress/strain
• Metal :

  A type of material typically made by processing an ore that has been mined or quarried
• Ores :

  typically an oxide of a metal, in the form of a rock
• Alloy: A mixture of two or more metals (or a metal with another element)
• Ferrous :

  a material that contains iron
• Non-Ferrous:

  a material that doesn't contain iron
• Cold Working :

  repeatedly bending or hammering a metal
• Work hardening:

  an increase in the strength and hardness of a metal due to cold working
• Annealing:

  a heat treatment that makes a metal softer and easier to work
• Hardening:

  a heat treatment that increases the hardness and strength of a metal due to a change in the arrangement of the atoms within it
• Quenching :

  The rapid cooling of a hot metal by immersing it in a liquid, often brine or oil
• Normalising :

  a heat treatment that results in metal that is tough with some ductility
• Corrosion:

  a reaction between the surface of a material and its environment that consumes some of the material
• Carburising :

  the addition of carbon to the surface of a low-carbon steel to improve hardness and strength
• Polymer:

  a type of material made from a large number of similar smaller chemical units that are bonded together
• Thermoplastics:

  A type of polymer that can be melted and re-shaped when heated
• Thermosetting polymer:

  A type of polymer with crosslinks between the polymer chains. It cannot be reshaped when heated.
• Composite material:

  A type of material made by combining two or more different types of material. These remain physically distinct within its structure.
• Reinforcement:

  The particles of fibre within a composite matrix that serve to increase its strength
• Timber :

  wood ; a type of material obtained from trees
• Ceramic :

  a type of material that is typically an oxide, nitride or carbide of a metal