High bandwidth temperature measurement in interrupted cutting of difficult to machine materials

High-speed milling is used across industries from aerospace to electronics. Tool wear can be affected by cutting interruptions in milling that lower tool-chip interface temperatures but also cause thermal and stress cycling. Micro-thermal imaging was used to determine the temperature during interrupted cutting of titanium alloy Ti6Al4V and AISI 4140 steel for percentage of time-in-cut from 100% to 10%. TiAlN/TiN coated carbide milling inserts were used with cutting speeds up to 180 and 640 m min⁻¹. This technique is the first to allow spatial mapping of thermal fluctuations on the tool which may be critical to determining causes for tool failure.