Tool Wear Characteristics of Micro Ruling of Optical Glass

摘要

Wear characteristics of small ball end mills in the micro milling process on optical glass are discussed. A method to measure loss of cutting edge is developed to observe the wear characteristics of glass milling. This method allows the loss of cutting edge to be determined from the surface profile of a machined surface with a numerical approach. Cutting tests are performed by changing of the attitude of the tool cutting edge and typical cutting conditions to verify the validity of the developed method and to observe the wear characteristics in glass milling. In this experiment, the loss of cutting edge is changed by tool attitude because the cutter velocity of actual cutting area is changed by tool attitude. On the other hand, the loss of cutting edge is not changed with the rotational speed and feed rate of the milling tool in which a crack-free surface can be obtained. In addition, diamond-coated carbide tools show high durability. However, they leave small brittle cracks on the machined surface. It is concluded that the flank wear does not grow enough to suppress the brittle crack because of the hardness of the diamond coat.