Resumo:
Machining processes stand out for being widely used in the automotive and aeronautical sectors, for their high rate of material removal, and ability to produce varied geometries. Duplex UNS S32205 stainless steel is a difficult material to machine due to its low thermal conductivity and hardening rate, making it a significant challenge for industries. This work addresses the end milling of UNS S32025 Stainless Steel, proposing innovative contributions in the optimization of machining parameters based on the Robust Parameter Design (PPR). The research presents an optimization strategy using the process capacity index, and in order to seek the real result of the process capacity taking into account the dispersion and centralization of the process average in relation to the specification limits, it was decided to use the Cpk capacity index, using the Taguchi methodology that combines the mean and variance in a single performance index, and in this way have a unique numerical value that reflects at the same time how close you will be to the desired goal and stability, dealing with a single equivalent answer. Input parameters such as cutting speed, feed per tooth, machining depth and working penetration were studied, considering as noise variables, tool flank wear, concentration and flow rate of the cutting fluid by means of a cross arrangement. With the results of the Experimental Development (DOE), it is sought to optimize the stability of the process and thus improve rework rates in this material. The confirmation experiments were performed using the Taguchi L9 arrangement. The results showed that the setups found through the optimization performed for the Cpk of Ra and Cpk of Rt are capable of producing a significant improvement in the top machining process of the stainless steel UNS S 32205, proving that the PPR-Cpk methodology is an excellent proposal.
