Análise do fresamento de ligas de ferro fundido nodular com nióbio

Abstract

This study analyzed the milling of niobium-alloyed ductile iron (0.18?0.347 wt.% Nb) using Taguchi L9 orthogonal array, varying depth of cut, cutting speed, feed rate, and Nb content, which identified feed rate (fz) as absolutely dominant for surface roughness (p < 0.05). Optimal levels were Fz = 0.10 mm/tooth, Nb = 0.25%, Vc = 250 m/min, and dynamic depth of cut (1.5 mm during 1-5 meters -> 0.5 mm during 7-9 meters), achieving Ra = 1.1 um and VBmax = 0.09 mm at 9 meters. Wear mechanisms transitioned sequentially abrasion, adhesion and probably oxidation, demonstrating that effective optimization requires dynamic parameter adjustment as machining progresses, rather than static level selection alone. [resumo fornecido pelo autor]