Experimental Investigation of Average Surface Roughness and Chip Morphology in End Milling of Aluminium Alloy 6151 Using Uncoated and TiAlN-Coated HSS Tools

Abstract

AbstractThe present work is aimed to investigate the impact of TiAlN coating on the high-speed steel tool top surface and cutting velocity in end milling of Aluminium alloy 6151 under a dry machining environment. The performance was assessed by the average surface roughness, scanning electron microscopic imaging of end mill cutters and chip morphology. The TiAlN-coated HSS end mill cutter experienced the very least amount of chip adhesion at all feed rates of cutting velocity: 30 m/min. However, such favourable condition was not observed at and above the cutting speed–feed combination: 60 m/min-200 mm/min. It was reflected in the escalation of average surface roughness and variation of chip morphology under the same chip load per tooth conditions. The average surface roughness obtained at the machining condition (Vc = 30 m/min – f = 100 mm/min) was 1.691 µm, which increased by 60% and 75% at the same chip load per tooth conditions 60–200 and 90–300, respectively. The uncoated HSS was considered as reference tool material for all the cutting conditions, which was not shown any improvement in machining performance at all the machining conditions than TiAlN-coated one.KeywordsAluminium 6151Surface roughnessChip morphologyChip adhesionBuilt-Up Edge (BUE)Built-Up Layer (BUL)