Wear form
The basic pattern of milling cutter wear is similar to that of turning tools. The cutting thickness of the high-speed tungsten carbide milling cutter is small, especially in the process of conventional milling, the cutter teeth extrude and slide on the surface of the workpiece are more serious, so the wear of the milling cutter mainly occurs in the back. When milling steel parts with tungsten carbide face milling cutter, due to the high cutting speed, the chips slide along the front at a large speed, so the back is worn at the same time, and the front is also worn with a small milling cutter.
The tungsten carbide face milling cutter performs high-speed interrupted cutting, so that the cutter teeth are subjected to repeated mechanical shock and thermal shock, resulting in cracks and fatigue damage of the cutter teeth. The higher the milling speed, the earlier and more severe this cutter wear will occur. Most tungsten carbide face milling cutters lose their cutting capacity due to fatigue breakage. If the geometric angle of the milling cutter is not selected reasonably or used improperly, and the strength of the cutter teeth is poor, the cutter teeth will produce no crack milling cutter wear after bearing a large impact force.
Preventive measures
(l) Reasonable selection of milling cutter insert grades: Insert materials with high toughness, low thermal crack sensitivity, and good heat resistance and wear resistance should be used. For example, YS30, YS25 and other grade inserts can be used when milling steel, and YD15 and other grade inserts can be used to prevent milling cutter wear.
(2) Reasonable selection of milling amount: under certain processing conditions, there is a safe working area that does not produce damage. Choosing Vc and ƒz in the safe working area can ensure the normal operation of the milling cutter and prevent the cutter from wearing.
(3) Reasonable selection of the relative position between the workpiece and the milling cutter: The reasonable selection of the installation position of the face milling cutter plays an important role in reducing the wear of the face milling cutter.
