Dislocation and strengthening mechanism on various materials Essay - 1

Dislocation and strengthening mechanism on various materials - Essay Example Composites are strengthened in a similar fashion by reinforcing the material matrix with particles or fibers. Fiber reinforced plastics (FRP) are the most commonly used composites [2]. The fibers act as load carrying mediums while the surrounding filler works to transmit the load to the fibers. At times polymers possessing higher material strength are required. There are three basic fundamental means of increasing material strength for polymers; these are crystallization, cross-linking and chain-stiffening [3]. Crystallization causes polymers to gain regularity in their molecular arrangement. Cross-linking is a process by which adjacent molecular chains are bonded with one other through covalent bonds. Chain-stiffening involves a number of methods through which chain bending is restricted. . Strengthening mechanisms for metals include grain size reduction, solid-solution strengthening and strain hardening. Grain size reduction involves reducing the grain size of the metal. The reduction in grain size obstructs dislocation motion when stress is applied. At a macro level, the material appears to have more strength. Solid-solution strengthening involves introducing impurity atoms in the interstitial solid solution. Strain hardening is also known as work hardening or cold work. Cold work is a process by which a ductile metal is plastically deformed resulting in a metal that is harder and stronger. Furthermore, recrystallization is a process by which a cold worked material regains its precold-worked properties. As mentioned afore, cold work or strain hardening is a inexpensive process by which a ductile metal is hardened through plastic deformation. The process is performed well below the absolute melting point of the metal [4]. There are a number of advantages related to strain hardening. The materials maybe strain hardened and molded into desired shape simultaneously while still being able to achieve superb dimensional tolerance and surface