Ultrasonic-Aided Laser Drilling of Aluminium-Based Metal Matrix Composites

In pulsed Nd: YAG laser drilling of aluminium-cased metal matrix composites (MMCs), it is well known that there are problems of limited maximum depth-of-drill, non-cylindrical hole profile and the presence of excessive re-cast material which are associated with the conventional process. A novel combined ultrasonic-laser machining technique has been developed to improve the overall quality of laser drilled holes. It has been proven that this ultrasonic-aided laser machining technique not only increases the depth-of-drill, but also improves the quality of the hole. A mathematical model is proposed to describe the shape of the machined hole.