Simulation and visualisation of vapour formation in submerged cutting of C45 and Inconel 718

Abstract Understanding the vaporisation of cutting fluids in machining processes is essential for improving cooling effectiveness and tool life. In order to gain basic knowledge regarding vapour formation, this study presents a combined experimental and numerical investigation of submerged turning of C45 and Inconel 718. High-speed imaging is employed to qualitatively visualise vapour phenomena, while simulations using the Finite Pointset Method (FPM) extend existing models to incorporate a physically realistic vapour phase and fluid–structure interaction. Jet cooling simulations capture the intermittent nature of vapour formation, with shorter time intervals and larger affected areas at higher wall temperatures. Increasing surface velocity shifts vaporisation farther from the stagnation point. Machining simulations indicate that cutting fluids tend to vaporise at a certain distance from the chip root rather than directly at it, while submerged machining experiments reveal a stable vapour region on the chip surface. These results advance the understanding of cooling performance and heat transfer in metal cutting and contribute to the development of more accurate simulation tools for process and tool optimization.