Vibration-assisted deep hole drilling of the aluminum material AlMgSi0.5

Abstract

When deep hole drilling problematic aluminum materials, the high ductility and adhesion tendency of these materials lead to the formation of built-up edges, long chips and material adhesions on the tool. This can not only cause rapid tool breakage, but also lead to significant damage to the borehole wall surface. In previous work, it has already been shown that these problems were avoided during vibration-assisted drilling with short tools. Compared to conventional drilling, in vibration-assisted drilling the feed motion is superimposed with a sinusoidal oscillation with a high amplitude and a low frequency resulting in a kinematic cut interruption and the generation of separated chips. The aim of this work is to investigate the extent to which the above mentioned problems encountered in conventional deep hole drilling of aluminum materials can be reduced by vibration-assisted deep hole drilling. To achieve this aim, experiments were carried out in conventional and vibration-assisted deep hole drilling. The chip geometry, feed forces, straightness deviation, surface temperatures and the surface quality of the borehole wall were used as evaluation criteria to compare both processes. It was demonstrated that the formation of built-up edges and material adhesions is avoided by vibration-assisted deep hole drilling. This results in a better surface quality of the borehole wall, what indicates less friction within the borehole due to the generation of small and separated instead of long chips. Since heat generation in vibration-assisted drilling is much lower than in conventional deep hole drilling, boreholes close to the workpiece surface were realized.