Wed Jun 08 11:45:42 CST 2022
As we all know, the metal cutting process due to chip deformation and friction, the cutting area produced high temperature, at the same time due to the cutting tool and workpiece material is different, formed a thermoelectric emf at both poles, produced a DC thermal current. Thermal current tends to intensify the oxidation process on the tool working surface and accelerate the tool wear. Under certain conditions, the tool and machine tool, workpiece and machine tool contact, as well as the friction pair between the machine tool itself in the contact area will also generate thermoelectric emf - thermal current.
In recent years, researchers at home and abroad have shown that the thermal current generated in the cutting process and the thermal current caused by other factors, these two thermal currents are through the machine tool - tool - workpiece - machine tool system to form a loop. At the same time, there is also a local thermal current circulating in the limited tool-workpiece contact zone, therefore, exacerbates tool wear. Therefore, in addition to the above basic ways to improve the cutting performance and durability of tools, a new way can be adopted to fight against the thermoelectric effect of cutting tool wear, that is, to cut off the thermoelectric circuit.
Cutting off the method of thermal current loop is very simple, even if the cutting tool and machine tool or workpiece and machine tool insulation, heat current through cutting area cannot form a loop, so that it can reduce the affinity between metal, reduce the devolop lump and the production of flake's burr, so as to improve the cutting performance, cutting tool to improve the machining quality and tool life.
How to cut the thermal current loop. For turning workers, on the upper and lower surface of the tool with a bakelwood pad tool plate or plastic pad tool plate, so that the upper and lower plane of the tool bar, side and the machine tool on the square tool holder insulation; For milling and planer, if the workpiece is clamped with flat pliers, the rubber board or rubber plate is inserted between the clamp and the workpiece, so that the workpiece is insulated with flat pliers; For drills and end mills, high strength plastic shank drills and end mills can be used to insulate the shank from the main shaft hole of the machine tool.
Through the production practice proved that cutting the thermal current loop is especially suitable for processing high strength, high hardness, hard cutting material processing can show its effect, usually can improve the cutting tool durability 1~ 2 times. Therefore, it is a relatively simple and easy to implement effective method.