Machinability of Al2024, Al6061, and Al5083 alloys using multi-hole simultaneous drilling approach

Aluminium alloys are extensively used in different industries due to their good mechanical properties, machinability, low cost and reliable inspection. Drilling is one of the most important machining processes for assembly operations. The number of holes required in an assembly may vary from several holes to millions depending on the application which increases the manufacturing time and costs. In this study, a multi-spindle drill head also known as the poly-drill head is used to perform multi-hole simultaneous drilling with the aim to increase productivity. Dry drilling tests are performed on Al2024, Al6061, and Al5083 aluminium alloys using uncoated carbide tools. Thrust force, hole quality in terms of surface roughness, burr and chip formation, as well as post-machining tool conditions, were investigated under different drilling parameters. Experimental results showed that Al2024 produced fewer burrs around the hole edges, less built-up edge on tools and formed short and broken chips. Holes machined in Al6061 alloy had a good surface roughness while lowest thrust force was recorded in holes drilled in Al5083 alloy.