Mechanical micromachining is becoming an important micro manufacturing process that uses drills (50μm diameter) and end mills (250μm diameter) to process engineering materials, such as steel, at the micro scale. However, burr formation at the surface of the workpiece threatens to render the part unusable. Previous work has shown that macro scale burr removal techniques cannot be employed at the micro scale. Therefore, the emphasis is on avoiding burr formation or reducing its size to an acceptable level.

Recently high speed machining has been gaining popularity at the micro scale; currently this involves rotational cutting speeds between 300,000-485,000 revolutions per minute (rpm). The reason for machining at high speeds is to maintain the recommended cutting speed (m/min) for that material. However, conventional micro machining speeds usually range from hundreds to several thousand rpm and these speeds are well below their recommended values. It is expected high cutting speeds at the micro scale will influence burr formation; particularly with regard to the generation of heat. This is because heat contributes to the re-welding of chips which form part of the burr and during high speed micro machining no evidence of high cutting temperatures has so far been observed.

This paper investigates the mechanisms of burr formation during conventional micro machining and high speed micro machining and explores methods of reducing and eliminating burr formation.