Micro groove cutting on the surfaces of Cu-B4C nanocomposites by fiber laser

Abstract

Micromachining has evolved into a key facilitating technology and is widely employed today for the creation of complex micro/nano surface features for the parts used in various industries like nano/micro electro-mechanical systems, medical and telecommunications. At present fiber lasers have made an increasingly significant contribution to micro-fabrications to generate intricate shapes. The increased usage of copper in micro-domains is attributed to the advancements in personal computing and telecom industry. Against this backdrop, this work focuses upon the production of micro-grooves on the surfaces of copper/nano-boron carbide (Cu-B4C) metal matrix nanocomposites (MMNCs) by 10 μm fiber laser spot beam. To begin with, Cu-B4C MMNCs were synthesized through the powder metallurgical route. Response Surface Methodology-I optimal design was then attempted to optimize the laser machining factors like laser power, number of passes, scanning speed and frequency with the intention to obtain the least surface roughness, minimum kerf width, lower heat affected zone, higher depth and higher material removal. An atomic force microscope is used to inspect the surface characteristics by measuring the roughness values of the surfaces adjacent to the top of micro-grooves. A 3D surface profiler investigated the depth of the groove produced by the fiber laser. Results indicate that a minimum surface roughness of 23.06 nm and a minimum kerf width of 35.49 μm are obtained in the run order 2. Similarly, the groove with a maximum depth of cut of 245.87 μm is achieved in the run order 3. Scanning electron microscopy images helped to examine the surface morphologies and heat-affected zone of the micro-grooved samples.