A study has been made of the effect of process parameters on the surface finish of drilled holes. Drills made of high-speed steel (HSS), tungsten carbide (WC), TiN-coated HSS, silicon nitride and aluminum oxide were used to drill holes in cast iron, 1018 steel and 6061 aluminum. The effect of chip morphology on finish was studied by controlled chip breakage achieved through the application of a controlled, superimposed modulation in the direction of drill feed. It has been found that drill material has the most important influence on surface finish with ceramic drills consistently giving the smoothest finish. Furthermore, the surface finish in the middle portion of a hole was consistently worse than at the top and at the bottom.
| Number of Pages : | 6 |
| Published : | 11/01/2000 |
