1 - Review of hole-making technology for composites

Abstract

Aircraft parts such as wing structures, spoilers and fairs, among others, consist of a great number of holes with different diameters, depths and surface finishes. These holes can be made by various methods, most commonly by traditional machining such as turning, drilling, and milling. However, in dealing with difficult-to-machine material such as composite, various considerations need to be taken into account. This is due to direct contact between tool and workpiece—the tool undergoes extreme wear and creates a great amount of heat, which induces residual stress that leads to degradation of both tool life and the quality of workpiece. As technology advances, the complexities of job profiles, hard materials, smooth surface finishes, and dimensional accuracy and tolerance has led to the replacement of traditional machining methods with nontraditional machining methods, as traditional machining is not always feasible, satisfying or economical due to various reasons. In this chapter, we review several technologies in hole-making for composites. The technology can be generally divided into machining and nonmachining technologies, and we review the capabilities and advantages of both.