Multi-objective optimization of Nd:Yag laser machining’s conflicting responses while milling micro-channels

Laser processing of materials finds application in micro-nano devices mainly because of its accuracy, flexibility, and ability to machine almost any material. Although it offers numerous advantages, it is a complex process involving a large number of factors. The quality of machining often depends on the appropriate selection of parameters. Moreover, the output responses in machining processes have conflicting nature; some are to be minimized, and others have to be maximized. This work uses grey relationship analysis coupled with principal component analysis for multi-response optimization of conflicting responses during laser machining of micro-channels. Micro-channels with a cross-sectional size of 200 × 100 µm were created using Nd:YAG laser beam micro-milling in steel alloy (AISI 1045). The scan speed, layer thickness, and scan strategy were found to have a significant effect on the dimensional accuracy of the microchannel. At the same time, the material removal rate was mostly influenced by layer thickness. Multi-response optimization results suggest low pulse frequency, high scan speed, low layer thickness, and S3 scan strategy for accurately fabricating micro-channels.