Machinability Investigation in Micro-Milling of Mg Based MMCs with Nano-Sized Particles

摘要

Magnesium based metal matrix composites (MMCs) have been employed in various areas such as automobile and aerospace due to their weight saving potential, high specific mechanical properties and excellent damping capacity. Recently, improved strength and ductility have been observed due to the incorporation of nano-sized reinforcements into magnesium. This paper presents the experimental results on the machinability of Mg based metal matrix composites (MMCs) with nano-sized particles (Mg/BN MMCs and Mg/ZnO MMCs) produced by liquid-state processing during micro-milling process. The effect of reinforcement materials and weight fraction, as well as the varying cutting parameters such as feed per tooth, spindle speed and depth of cut on the cutting force, surface morphology and chip formation were studied. The results show that the cutting force for machining pure Mg is larger than that for other MMCs specimen except of Mg/2.5 wt% ZnO and MMCs reinforced containing ZnO particles exhibit higher cutting force than that containing BN particles. Moreover, compared to the pure Mg, chips with different morphology can be found in machining MMCs.