A high-frequency non-resonant elliptical vibration-assisted cutting device for diamond turning microstructured surfaces

Abstract

In recent years, research has begun to focus on the development of non-resonant elliptical vibration-assisted cutting (EVC) devices, because this technique offers good flexibility in manufacturing a wide range of periodic microstructures with different wavelengths and heights. However, existing non-resonant EVC devices for diamond turning can only operate at relatively low frequencies, which limits their machining efficiencies and attainable microstructures. This paper concerns the design and performance analysis of a non-resonant EVC device to overcome the challenge of low operational frequency. The structural design of the non-resonant EVC device was proposed, adopting the leaf spring flexure hinge (LSFH) and notch hinge prismatic joint (NHPJ) to mitigate the cross-axis coupling of the reciprocating displacements of the diamond tool and to combine them into an elliptical trajectory. Finite element analysis (FEA) using the mapped meshing method was performed to assist the determination of the key dimensional parameters of the flexure hinges in achieving high operational frequency while considering the cross-axis coupling and modal characteristics. The impact of the thickness of the LSFH on the sequence of the vibrational mode shape for the non-resonant EVC device was also quantitatively revealed in this study. Moreover, a reduction in the thickness of the LSFH can reduce the natural frequency of the non-resonant EVC device, thereby influencing the upper limit of its operational frequency. It was also found that a decrease in the neck thickness of the NHPJ can reduce the coupling ratio. Experimental tests were conducted to systematically evaluate the heat generation, cross-axis coupling, modal characteristics and diamond tool’s elliptical trajectory of a prototype of the designed device. The test results showed that it could operate at a high frequency of up to 5 kHz. The cross-axis coupling ratio and heat generation of the prototype are both at an acceptable level. The machining flexibility and accuracy of the device in generating microstructures of different wavelengths and heights through tuning operational frequency and input voltage have also been demonstrated via manufacturing the micro-dimple arrays and two-tier microstructured surfaces. High-precision microstructures were obtained with 1.26% and 10.67% machining errors in wavelength and height, respectively.

Elliptical vibration chiseling: a novel process for texturing ultra-high-aspect-ratio microstructures on the metallic surface

“…Moreover, vibration-assisted cutting can be very efficient for large-area microstructure texturing with a texturing rate of as high as 20 000•s −1 if an ultrasonic tool vibration is adopted. Currently, the surface texturing principle based on vibration-assisted cutting has been realized in turning [52], milling [53], planning [54], and so on. In addition to single-scale structures like dimples [55,56] and grooves [57], vibration-assisted cutting can also fabricate hierarchical microstructures like multiscale microchannels [58] and multiscale dimples [59], which have improved performance in applications such as heat transfer [60], anti-fouling [61], and cell bioactivity [62].…”

Simulation and Experimental Study of Non-Resonant Vibration-Assisted Lapping of SiCp/Al

“…Researchers have tried to apply the non-resonant vibration device to vibration-assisted cutting (VC) [ 23 , 24 ], vibration-assisted milling (VM) [ 25 ], and vibration-assisted polishing (VP) [ 26 , 27 ] and achieved good results. Zhou et al designed an elliptical VC device and studied the removal mechanism, cutting force, surface roughness, and microstructure in elliptical VC.…”

Insight into Atomic-Scale Adhesion at the C–Cu Interface During the Initial Stage of Nanoindentation

“…Numerous researchers have investigated the machining of copper using diamond tools using experimental and theoretical methods [16][17][18][19][20]. However, the nature of adhesion and atomic effects have rarely been investigated.…”