ABSTRACT
Generally, composites are manufactured by mixing together two separate components, one of which forms a continuous matrix whilst the other, present either as particles or fibres, provides the strength or hardness required in the composite material. This chapter provides an even more effective barrier to any further dislocation fronts following along the same plane. An example of such a dispersion-hardened material is 'Sintered Aluminium Powder' (SAP) in which the dispersed strong particles or 'dispersoid' is aluminium oxide. These are composite materials in which a hardened paste of 'cement' and water is used to stick and hold together particles of sand, gravel, stones and other 'aggregates' to give fairly high compressive strength materials. Mortar is the adhesive material used between bricks in the building industry. Before the advent of Portland cement, mortar consisted of a mixture of slaked lime, sand and water. Concrete is produced from a mouldable mixture of Portland cement, stone aggregate, sand and water.
