Experiment based investigation into micro machinability of Mg based metal matrix composites (MMCs) with nano-sized reinforcements

As a composite material with combination of low weight and high engineering strength, metal matrix composites (MMC) have been utilized in numerous area such as aerospace, automobile, medical and optics in the past two decades. With the increasing demand on miniaturized products with enhanced mechanical properties, micro milling has been employed to manufacture the MMC component. However it is recognised as a difficult-to-cut materials due to its improved strength. This paper presents the micro machinability of Mg based metal matrix composites reinforced with nano-sized particles. The influence of cutting parameters on the surface morphology and cutting force was studied. The specific cutting energy, cutting force and surface morphology, whilst the minimum chip thickness was characterised with the aim of examining the size effect. The results show that depth of cut and spindle speed have significant effect on the surface roughness. The higher cutting force and worse machined surface were obtained at the small feed per tooth ranging from 0.15 to 0.5 μm/tooth due to the size effect.