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.