Engineering Matrix Materials for Composites: Their Variety, Scope and Applications

Matrices are essentially binders for the reinforcements of composite material. Appropriate selection of fine chemicals is vital for the creation of desired matrices for generating composite materials. In fact, matrix is a subclass of a composite material. Matrices are generally of four kinds such as (i) polymer (hard as well as flexible), (ii) metal, (iii) ceramic, and (iv) cement. Each type of these subclasses of the matrix is discussed with a brief of their pros and cons. Polymer matrices are generally organic based whereas metal or ceramic matrices are inorganic in nature. Hard plastic matrix as well as flexible rubbery matrix are also discussed in the light of their applications. Carbon as matrix material for hi-tech C/C (carbon/carbon) composite materials is also stated. Cement is a special kind of inorganic matrix material because of its very special solidification mechanism during the formation of concrete composite; and it carries bulk values in the engineering area. For higher temperatures, carbon, ceramic or metal matrix materials are useful. Ceramics possess various conductivities, but they have poor tensile strength despite their ability to afford high-temperature products. Generally lightweight metals such as titanium, aluminum, magnesium, and intermetallics such as Ni-aluminide and Ti-aluminide are used; and the operating temperature can be extended to 2000 °C. The advantages of metal matrices are higher strength and ductility than those of polymers. Carbon matrix based carbon/carbon (C/C) composites can be used even at the temperature of ~3000 °C, but are preferred only in critical engineering areas of applications. Different types of matrix material may also prove to be efficacious constituent item for innovative design of integrated structure in the ever challenging area of Blast and penetration resistant materials (BPRM).