Evaluation of CuttingTool Coating on the Surface Roughness ...
a1,b1,c1 Builtup edge and aluminum spread adhesion a2,b2,c2 surface pitting and aluminum buildup on tools tip a3,b3,c3 aluminum filling the surface pitting. The SEM images in Figure 12 revelated that the burr formation and hole edge quality at the exit was the worst when drilling using TiNcoated tools, followed by TiAlNcoated tools.