Ultrasonic-assisted abrasive micro-deburring of micromachined metallic alloys

Abstract

Burr formation is a common and undesirable phenomenon in metal cutting operations, reducing the quality, accuracy, and functionality of the component. In micromachining, burrs are smaller but comparable to the feature size and are difficult to remove. Most of the traditional deburring operations cannot be applied to micromachined components without proper scaling, as the feature size on the part is very small and is prone to damage. Ultrasonic energy is widely used for part cleaning. In this study, an ultrasonic-assisted abrasive micro-deburring process using a probe sonicator has been developed to remove burrs from micromilled components on a variety of metallic alloys with a focus on burr removal, preservation of dimensional accuracy of the channels, minimisation of surface damage, and improvement in surface finish. Deburring of micromilled channels of 500 μm width on aluminium 6061, copper, Ti-6Al-4 V, and bearing steel has been conducted, and the results have been analysed. Deburring occurred due to the impact of abrasives, which were accelerated by the energy of the collapsing cavitation bubbles. Burr reduction by as much as 92 % has been achieved in a very short time of ten seconds for soft materials like Al 6061 and copper, and three to six minutes for Ti-6Al-4 V and bearing steel, without damaging the components or inducing any deterioration of dimensional accuracy. The surface roughness of channels has decreased from 8.97 nm to 6.63 nm after ten seconds deburring, resulting in a 26 % improvement in surface finish.