GCSE Revision Resistant materials MISS HUGHES GCSE Revision Resistant materials Jenny Hughes

MATERIAL PROPERTIES ELASTICITY The tendency of solid materials to return to their original shape after being deformed. Solid objects will deform when forces are applied on them. If the material is elastic, the object will return to its initial shape and size when these forces are removed. The opposite of plasticity. PLASTICITY  The deformation of a material undergoing non-reversible changes of shape in response to applied forces. The opposite of elasticity.

MATERIAL PROPERTIES COMPRESSIVE STRENGTH The ability of a material to resist forces that attempt to squeeze or compress the material together. The opposite of tensile strength. TENSILE STRENGTH  The maximum stress that a material can withstand while being stretched or pulled before failing or breaking. Tensile strength is the opposite of compressive strength and the values can be quite different.

MATERIAL PROPERTIES FUSIBILITY  The ease with which a material will melt. Materials such as solder require a low melting point so that when heat is applied to a joint, the solder will melt before the materials being soldered melt, i.e. high fusibility. HARDNESS The measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied.

MATERIAL PROPERTIES BRITTLENESS The tendency of a material to fracture or fail upon the application of a relatively small amount of force, impact, or shock. The opposite of toughness. TOUGHNESS  The ability of a material to absorb energy and plastically deform without fracturing. The opposite of brittleness. FLEXIBILTY The measure of a material's ability to flex or bend. Flexible materials are better able to absorb impact without breaking.

MATERIAL PROPERTIES DUCTILITY  A solid material's ability to deform under tensile stress; this is often characterised by the material's ability to be stretched into a wire, see diagram (c). MALLEABILITY A material's ability to deform under compressive stress; this is often characterised by the material's ability to form a thin sheet by hammering or rolling. Both of these mechanical properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture.

MATERIAL PROCESSES As a group we discussed the different material processes and how they could be manufactured. The three processes are: ADDITION (FABRICATION) The joining of materials including; thermal, mechanical and technical techniques. WASTAGE Cutting away unwanted parts using hand or machine tools. REDISTRIBUTION DEFORMING: Changing the shape of the material. REFORMING: Liquefied metals or plastics are poured into a mould.