How Micro-Geometry of Cutting Edges Influences Surface Integrity

Sammanfattning

The aerospace industry relies heavily on the structural integrity of machined components.Even the smallest surface and subsurface defects can drastically reducethe components’ fatigue life, possibly resulting in catastrophic failure. This thesisquantitatively evaluates the impact of cutting edge micro-geometry. Specifically,how edge radius and symmetry affect surface integrity during the machining of Ti-6Al-4V.A fundamental experimental study has been conducted to investigate how changesin a cutting edge’s sharpness and shape, its micro-geometry, affect the surface integrityof the machined part. A series of orthogonal cutting tests in Ti-6Al-4Vwas made to investigate the elementary relationship between cutting edge microgeometryand surface integrity under different cutting conditions. The results areevaluated through regression analysis to statistically describe the relationships.It was found that cutting tools with larger radii and waterfall-shaped edges stronglyimpact surface integrity, regardless of variations in cutting speed and depth of cut.Other surface integrity variables, however, do depend on cutting speed and depthof cut, not just on cutting edge micro-geometry.