In this article, the effect of vibration amplitude during ultrasonic elliptical vibration–assisted turning on cutting tool flank wear ( VBmax) and tool diffusion wear mechanism has been experimentally studied in machining of AISI 4140 hardened steel. To achieve this goal, an ultrasonic elliptical vibration–assisted turning setup was designed and manufactured. This device was then used in both ultrasonic-assisted tuning and ultrasonic elliptical vibration–assisted turning tests (i.e. one-dimensional and two-dimensional ultrasonic-assisted machining). According to the achieved results, ultrasonic elliptical vibration–assisted turning is more effective than ultrasonic-assisted tuning in reducing tool flank wear; at an amplitude of 13 μm, work velocity of 180 mm/s and feed of 0.09 mm/rev, VBmax were decreased 30.3% and 54.3%, respectively, in case of ultrasonic-assisted tuning and ultrasonic elliptical vibration–assisted turning. It was also observed that increasing the amplitude of ultrasonic vibrations reduces VBmax; at work velocity of 180 mm/s and feed of 0.09 mm/rev, the reduction of VBmax in ultrasonic elliptical vibration–assisted turning with amplitudes of 5 and 13 μm is, respectively, 39.3% and 54.3%, compared with that of conventional machining. The results also show that the application of ultrasonic vibrations weakens the cutting tool diffusion wear mechanism. This attenuation is much higher for ultrasonic elliptical vibration–assisted turning in comparison to ultrasonic-assisted tuning. Besides, the amount of attenuation in cutting tool diffusion wear mechanism decreases with increasing vibration amplitude.

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Nowadays, laser drilling has found extensive medical applications such as drilling of titanium implants. However, laser drilling of such implants has encountered several restrictions such as low penetration depth, high thickness of recast layer and heat affected zone (HAZ). Therefore, various approaches such as magnetic field and/or ultrasonic vibration aided laser drilling have been proposed to overcome these limitations; among them, few studies have been conducted considering the simultaneous effect of magnetic field and ultrasonic vibrations on microstructural characteristics. Therefore, in the present paper, the effects of magnetic field intensity and ultrasonic vibration amplitude (with a frequency of 28 kHz) have been investigated on the formed phases, thickness of recast layer and thickness of HAZ in laser drilling of Ti6Al4V. According to the obtained results, adding ultrasonic vibrations to the laser drilling process will lead to an average decrease of 29.40% and 28% respectively for the thickness of HAZ and recast layer. However, with the addition of a magnetic field (0.1 Tesla), the thicknesses of HAZ and recast layer were increased by 7% and 11%, respectively. Furthermore, increasing the ultrasonic vibration amplitude was associated with the increase in the acicular alpha phase (α′) as well as more dense, and fine-grained and uniform structure. This can be attributed to the strengthening of convective heat transfer mechanism and higher cooling rate. Additionally, by increasing the intensity of the magnetic field, the structure of the acicular alpha (α′) became finer and the density of lateral branches decreased.