Carbon short fibers reinforced polymer composites are commonly used composite materials in automotive and aerospace industries. In the present work, nickel coated carbon polyacrylonitrile (PAN)-based carbon fibers/epoxy manufactured by open molding method were studied. Also, nickel coated carbon fiber /epoxy composites with aluminium oxide nano filler were evaluated. Addition of small proportions of 100 nm size Al₂O₃ fillers significantly enhanced the mechanical properties of polymer matrix composites. In nickel coated carbon fiber /epoxy composites the Al₂O₃ nano fillers were added with different weight percentage varied from zero to six percent in steps of two percent. All the tests were conducted according to ASTM standards. The results revealed that Al₂O₃ nano fillers reinforced composites exhibited enhanced mechanical properties such as tensile strength, impact strength and fracture toughness.

Polymer matrix composites are emerging materials for various industries, such as automotive, aerospace, and marine industries, due to their distinct mechanical and physical properties. In these applications, different machining processes are essential to obtain required shape and features of composites, assembling various components, and many other uses. The machinability has the significant impact on the properties of polymer composites, and it mainly depends on the reinforcements/fillers used in the polymer composites. This chapter covers the influence of fillers on mechanical properties and machining processes of fibre-reinforced polymers (FRPs). It also includes the effect of fibre loading and its orientation, type, size, and filler loading on machining process of FRPs. <!----> <!----> <!----> <!---->