Laser-assisted milling strategies with different cutting tool paths

Laser-assisted machining (LAM) is becoming recognised as a process that can enhance the machinability of many difficult to machine materials. The process uses a laser beam to heat and soften the workpiece thereby making it easier to cut. While some fundamental research aspects of the process are becoming well understood, one practical challenge facing engineers is to develop a method for using this technology to machine complex components by milling. In particular, there is a requirement to incorporate LAM into current machining environments and with current machining equipment with minimum need for new equipment. In milling processes, the cutter follows a complex predetermined tool path so the challenge for successful laser-assisted milling is to ensure that the laser beam also follows this tool path and is always heating material directly ahead of the cutter. This paper presents two low-cost methods which can be employed to achieve this. The first method involves using a fixed position laser, a rotating machine table and careful tool path selection. The second method involves using a laser that rotates around the machine spindle which accommodates changes in the cutting direction. Each process is described in detail, and an example is given where a standard CNC milling machine is retrofitted for LAM.