Despite advancements in cutting processes and development of cutting tools, the use of cooling and lubrication fluids (CLF) remains essential in most machining operations, prompting the creation of innovative cooling and lubrication technologies. In addition to concepts in which cryogenic media are used for cooling, High-Pressure (HP) CLF systems are increasingly used for machining difficult-to-cut materials, offering benefits like longer tool life, lower cutting zone temperatures, higher cutting speeds, and improved productivity However, the use of this technology is severely limited due to the high CLF jet speeds, the highly accelerated chips (which damage the machined surface), and high power consumption. As an approach to address the problem and alter the physical interactions that occur during HP cutting process, an innovative idea or concept of pulsating high-pressure CLF supply is presented in this doctoral thesis. As part of the dissertation, a system was developed for sequential control of the cutting process with the support of the HP jet, which controls the flow and pressure of the supplied CLF and thus influences the lubrication, cooling and chip breaking effect in the cutting process. By integrating the developed system into a machining center, the fundamental operation was analysed in turning processes, the physical mechanisms were identified, and the fundamental characteristics of pulsating HP machining were determined based on chips, tool durability, cutting forces, cutting temperatures, surface integrity of the machined part, and electricity consumption. The use of pulsed CL supply offers the possibility to actively control the chip shape. Therefore, a model was developed to predict chip deformation and determine the critical moment for chip breakage. Analysis demonstrated the feasibility of using the pulsed HP CLF system in turning processes, reducing tool wear, improving surface quality, and increasing productivity by controlling chip length.
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