INFLUENCE OF CUTTING CONDITIONS ON SURFACE ROUGHNESS OF PA AND PA15

Abstract

Engineering polymers, particularly polyamides, are increasingly used due to their favorable properties; however, their machinability—especially in the case of glass fiber-reinforced composites—remains a challenge. Conflicting findings in the literature regarding the effect of fillers on surface finish, particularly for composites with lower fiber content, highlight the need for further investigation. In this context, the present study focuses on the experimental examination of the influence of milling parameters on the surface roughness of two materials: pure polyamide (PA) and a composite containing 15% glass fibers (PA15). Milling was executed on a HAAS Tool Room Mill CNC system, employing a 4 mm standard end milling cutter. For each material, various machining regimes were applied, combining three spindle speeds and three feed rates. Surface roughness was evaluated using Ra and Rmax parameters in accordance with ISO 4287, and measurements were conducted with an ISR-C002 profilometer. The obtained results show that PA exhibits lower Ra and Rmax values compared to PA15, along with more stable behavior across all machining regimes. PA15 demonstrated higher roughness and variability. The most favorable results for both materials were achieved at higher spindle speeds and moderate feed rates. This study contributes to a better understanding of the relationship between material composition and machining parameters, providing valuable insights for optimizing surface quality in polymer composites.