Influence of Hydraulic and Interference-fit Tool Holders on Tool Wear and Hole Quality in the Drilling of Al-Si Cylinder Heads

The present work compares the performance hydraulic and interference-fit tool holders in the machining of Al-Si cylinder head components produced by pressure casting for the automotive industry by analyzing tool wear as well as geometry, roughness and tolerance of the produced holes. Uncoated WC + Co cutting tools were applied and the drilling operations were carried out at a Hüller computer numerical controlled machining center. Tool wear was characterized by applying optical and scanning electron microscopy and geometry of the holes was followed for parts 1 to 11500. The investigations revealed that, while no significant difference in tool wear could be detected, better results with respect to hole diameter, roundness and surface roughness were obtained for the drills fixed by thermal interference.