Zhong Z., Ke P., Chia B.

Aluminum-based metal matrix composite (MMC) reinforced with Al2O3 or SiC particles are advanced materials. However, full implementation of MMCs is cost-prohibitive, partially because of the materials’ poor machinability. Therefore, diamond turning and grinding of MMCs have been carried out to improve the surface integrity. This paper presents the investigation results obtained from the finite element simulations and experiments of a non-conventional cutting technique: turning of an aluminium-based metal matrix composite with ultrasonic vibrations. The investigation involved the finite element modelling of the orthogonal cutting operation with vibrations using ANSYS. The aims were to verify the advantages of ultrasonic-assisted cutting over the conventional machining, and to investigate the effects of the vibration amplitude on the cutting forces and contact stresses induced during the turning process. With the simplifications and assumptions made in the simulations, the results displayed trends, which were in agreement with an experimental study reported in the literature. The ultrasonic-assisted cutting technique can relieve the tool and the workpiece from the continuously induced stress compared to the conventional cutting method. It is believed that this non-conventional cutting technique is suitable for cutting difficult-to-machine materials. An ultrasonic vibration device was also designed and fabricated. A theory was devised to explain how ultrasonic-assisted turning works, identifying the effects of the parameters that significantly affect the surface produced. Experiments of turning a MMC were then carried out, and the results showed that cutting speed also affected the surface finish significantly. When turning and vibration parameters were properly determined, surface finish of the MMC samples turned with ultrasonic vibrations was better than that of the MMC sample cut without ultrasonic vibrations.