Novel ultrasonic horn design for machining advanced brittle composites: A step forward towards green and sustainable manufacturing

Abstract

Ultrasonic assisted machining is a proven green and sustainable manufacturing technology owing to low power consumption, no/low usage of lubricant, pollution free nature of the process, excellent machining quality and enhanced tool life. Performance of ultrasonic assisted machining system greatly depends on the amplitude of vibration of the tool, achieved through an ultrasonic horn, design of which is a main interest of researchers. Higher vibration amplification helps achieve good machining quality, minimizes wastes and produces dust free environment. In current research work, novel ultrasonic horn has been deigned to achieve higher vibration amplitude at tool end for ultrasonic machining of advanced brittle composites. 3rd order polynomial equation was used to define horn profile, having resonant frequency closer but greater than generator’s excitation frequency for high magnification factor. Modal and harmonic analyses were carried out to compute axial modal frequency, vibration amplitude, magnification factor and stresses numerically. Performance of newly designed ultrasonic horn was observed to be much better than that of state of the art of standard horn designs in terms of vibration amplification within safe working stress limits. With the same dimensions, the results were compared and found to be in good agreement with the past research. The magnification factor for novel horn design was observed to be 77.56% and 62.73 % higher as compared to that of step and 3rd order Bezier horns. Gaussian horn was also found to provide high vibration amplification when designed with axial modal frequency greater than the generator frequency. • Evaluates standard ultrasonic standard horn designs for machining advanced brittle composites. • Proposes a novel ultrasonic horn design to achieve higher vibration amplification. • Evaluates ultrasonic horns at axial modal frequency greater than generator frequency. • Highlights merits and demerits of ultrasonic horns for frequency ratio less than 1. • Offers recommendations for future work.