Sustainability-driven optimization of ultrasonic atomization-assisted micro milling process with ceramic matrix composite

Abstract

The micro milling of ceramic matrix composites poses huge challenges in machining process as the anisotropic characteristic, strength-to-weight ratio and high cutting temperature. Apart from that, the emission and disposal of lubrication liquids have a negative impact on the environment conservation. In order to acquire better machinability of ceramic matrix composites, a new micro milling technique integrated with ultrasonic atomization based on water-based lubricating agent and coolant is presented in this work. Correspondingly, the novel sustainability-driven optimization framework of machining parameters is developed for the proposed ultrasonic atomization-assisted micro milling operation. The integration criteria of sustainability assessment with manufacturing process and machined product have been investigated in the technical, economic and environmental aspects, in which tool remaining useful life, stochastic machining process variables, surface quality of machine product, machining cost and carbon emission are included. The estimation accuracy of the related sustainability criteria are validated with a series of machining conditions. The proposed tool remaining useful life prediction method can significantly improve the ultimate life of micro cutting tool, the average prediction errors of cutting forces, energy consumption and surface roughness are 11.83%, 9.60% and 11.02%, meanwhile, the machining cost and carbon emission can also be reduced with ultrasonic atomization lubrication compared to those under flood fluids. Then, on the basis of the overall sustainability criteria, the multi-objective optimization framework is carried out to obtain the optimal machining parameters with the improved cuckoo search methodology, wherein the dimensionality of multiple variables is reduced by the principal component analysis. The comparison results about preferred and optimal machining parameters, and the related radial diagram of integral sustainability performance index validate that the sustainability performance of ultrasonic atomization-assisted micro milling operation could be enhanced by the proposed comprehensive optimization framework. The developed sustainability-driven optimization system offers a basis for the sustainable micro manufacturing technique of difficult-to-cut composite materials.