Deep drilling of aluminium die-cast parts: surface roughness, dimensional tolerance and tool-chip interaction

Many automotive applications require deep drilling on pressure die-cast parts in Aluminium alloys. The aim of the research was to understand if common cutting practices, usually determined on raw materials, can be successful on semimanufactured parts as well, having an inhomogeneous microstructure. A specific investigation was carried out on deep drilling of an EN AB-46000 cylinder block, varying technological parameters (cutting speed, feed, tool, lubrication). Dimensional tolerance and surface roughness were measured and statistically analyzed. The quantitative analysis of the process macroscopic performances was combined with an investigation of microstructural aspects of the material, their effects on chip formation and tool-chip interaction.