Comportamento de revestimentos de ferramentas de corte no fresamento do Inconel 718

Abstract

This study aimed to investigate the influence of different coatings applied to solid carbide end mills in the end milling of Inconel 718, a nickel-based superalloy characterized by high mechanical strength and low machinability. Three commercial coatings (ALCRONA EVO® (AlCrN), TISAFLEX® (AlTiN/TiSiXN), and LATUMA® (AlTiN)) were evaluated, in addition to an uncoated condition, under different combinations of cutting speed (50 and 80 m/min) and feed per tooth (0.035 and 0.070 mm/tooth). The experimental tests included the analysis of tool life, surface roughness, cutting temperature, cutting forces, and chip morphology. Tool life was determined based on a maximum flank wear criterion of 0.3 mm and expressed in terms of volume of material removed. Surface roughness was evaluated using the Ra parameter, temperature was measured by infrared thermography under dry conditions, and cutting forces were monitored using a piezoelectric rotating dynamometer. Chip morphology was qualitatively analyzed using optical microscopy. The results showed that tool performance was significantly influenced by the coating, with TISAFLEX® exhibiting the best performance and longest tool life, while the uncoated tool showed the poorest results. Feed per tooth was identified as the most influential parameter, leading to reduced tool life and increased surface roughness (Ra) and cutting forces. Temperature measurements presented relatively low values, attributed to the short cutting length, although an increasing trend was observed along the cutting pass. The chips exhibited similar geometry across the evaluated conditions, being more influenced by the cutting parameters than by the coating. Overall, the results demonstrate that the proper combination of coating and cutting parameters is essential to improve the milling of Inconel 718, contributing to enhance the tool life and surface quality.