Mar 23, 2020
During the milling process of the tungsten steel milling cutter, the workpiece can be fed along or relative to the tool rotation direction, which will affect the starting and finishing characteristics of the cutting.
When the tungsten steel milling cutter performs down milling (also called co-directional milling), the workpiece feed direction is the same as the tungsten steel milling cutter rotation direction in the cutting area. The chip thickness will gradually decrease from the beginning until the end of the cut is zero when performing peripheral milling; in the reverse milling (also known as reverse milling), the feed direction of the workpiece and the milling cutter rotation of the cutting area The direction is exactly the opposite. The chip thickness starts at zero and then increases gradually as the cutting process progresses.
When the tungsten steel milling cutter is back-milled, the tungsten steel milling cutter blade starts cutting from zero chip thickness, which will generate a high cutting force, which pushes the tungsten steel milling cutter and the workpiece away from each other. After being forced into the incision, the tungsten steel milling cutter blade usually comes into contact with the hardened surface caused by the cutting insert, and at the same time produces friction and polishing effects under the action of friction and high temperature. Cutting forces also make it easier to lift the workpiece off the table.
When the tungsten steel milling cutter performs down milling, the tungsten steel milling cutter starts cutting from the maximum chip thickness. This can avoid polishing effects by reducing heat and weakening the tendency to process hardening. It is very advantageous to apply the maximum chip thickness, and the cutting force makes it easier to push the workpiece into the tungsten steel milling cutter, so that the tungsten steel milling cutter blade performs the cutting action.
When milling a tungsten steel milling cutter, chip breaking sometimes adheres or welds to the cutting edge and gathers around the beginning of the next edge cutting. When performing back milling, chip breaking is relatively easy to be trapped or wedged between the insert and the workpiece, which can cause the insert to break. When performing down milling, the same chip breaking will be divided into two, so that the cutting edge will not be damaged.
Regardless of the requirements of the machine, fixture and workpiece, down milling is the preferred method.
Because the cutting force is easy to push the blade forward while keeping the workpiece down, the down milling has certain special requirements on the machining process. This requires the machine to handle the table feed requirements by eliminating backlash. If the tool is pushed into the workpiece, the feed will increase irregularly, resulting in excessive chip thickness and chipping. In such applications, up milling should be selected. In addition, if the machining allowance changes greatly, it is more advantageous to choose up-milling at this time. To clamp the workpiece correctly, it is necessary to have the proper clamps, as well as the correct tool size for the job. But for the vibration trend, the cutting force direction is more important.