Machining of Kevlar Aramid fiber reinforced polymer composite laminates (K-1226) using solid carbide step drill K34

Abstract

The aerospace industry is using composite materials for numerous components and structures. Many of these components require machining during its fabrication. Drilling of composite materials is difficult to carry out due to damage being introduced into the component in the form of delamination, fiber pullout, and local cracks. Further, rapid wear development in the cutting tool also takes place during drilling of composite materials. Conventional machining processes such as turning, drilling or milling can be applied to composite materials, provided proper tool design and operating conditions are adopted. Kevlar Aramid Fiber Reinforced Plastics (K-1226) is widely used in the industry due to its chemical stability at high temperature and resistance to wear. Studies show that conventional cutting of this laminates are extremely difficult due to the frictional force developed via thermal expansion of substrate material. This has restricted the Kevlar component usage. In this regard, present paper describes the effective method for drilling K-1226 material of varying thickness 10mm and 12mm using solid carbide step drill K-34 to drill a hole of 9mm diameter; The drilled Laminates are examined using C-Scan Analysis.