Liquid covered micro-milling

Micro-milling tools made of cemented carbide suffer from fast tool wear and random tool breakage during the machining process. The cutting material cemented carbide is composed of a hard material phase made of tungsten carbide and a binder phase made of cobalt. An allotropical crystal lattice transformation of the binder phase at a temperature TH = 420 °C leads to increased tool wear. Commonly minimum quantity lubrication (MQL) is used as cooling lubricant technology in micro-milling. In this work a new liquid covered cooling lubricant (LCCL) technology and the commonly used MQL technology were compared regarding tool wear of cemented carbide tools for machining the steel STAVAX ESU. In the LCCL technology the cutting process is completely covered with cutting lubricant. It could be concluded that the new LCCL technology offers a high potential to reduce the tool wear in micro-milling of steel with cemented carbide micro-milling tools.