As the most important advanced manufacturing technology in mold manufacturing, high-speed machining is an advanced manufacturing technology with high efficiency, high quality and low consumption. A series of problems in conventional cutting have been solved by the application of high-speed machining.
The cutting speed and feed speed are improved in series compared with the traditional cutting process, and the cutting mechanism has also changed fundamentally. Compared with traditional cutting, high-speed machining has made a substantial leap. The metal removal rate per unit power is increased by 30% ~ 40%, the cutting force is reduced by 30%, the cutting life of the tool is increased by 70%, the cutting heat left in the workpiece is greatly reduced, and the low-order cutting vibration is almost eliminated.
With the increase of cutting speed, the removal rate of blank material per unit time increases, the cutting time decreases, and the processing efficiency improves, thus shortening the manufacturing cycle of products and improving the market competitiveness of products. At the same time, the small amount of fast forward of high-speed machining reduces the cutting force, and the high-speed removal of chips reduces the cutting force and thermal stress deformation of the workpiece, and improves the possibility of cutting poor rigidity and thin-walled parts. Due to the reduction of cutting force and the increase of rotation speed, the working frequency of the cutting system is far from the low-order natural frequency of the machine tool, and the surface roughness of the workpiece is most sensitive to the low-order frequency, thus reducing the surface roughness.
In the machining process of the high hardened steel parts (hrc45-65) of the mold, the use of high speed can replace the process of electrical machining and grinding and polishing, avoid the electrode manufacturing and time-consuming electrical machining time, and greatly reduce the amount of grinding and polishing of the fitter. High speed milling can be successfully completed for some thin-walled die workpieces that are more and more needed in the market. Moreover, on the high-speed milling CNC machining center, the mold can be clamped once to complete multi-step machining. These advantages are very suitable for die and mould industries with fast capital turnover requirements, urgent delivery time and fierce product competition.
High speed machining system is mainly composed of high-speed machining center, high-performance tool clamping system, high-speed tools, safe and reliable high-speed cam software system, etc. Therefore, high-speed machining is essentially a large system engineering. With the development of cutting tool technology, high-speed machining has been applied to the processing of alloy steel (HRC > 30), and is widely used in the processing of stamping dies, injection molds and other parts in automotive and electronic components. The definition of high-speed machining depends on the type of workpiece material being processed. For example, the cutting speed used for high-speed processing of alloy steel is 500 m / min, which is the conventional down milling speed when processing aluminum alloy.
With the expansion of the application scope of high-speed machining, the research on new tool materials, the improvement of tool design structure, the generation of new CNC tool path strategies and the improvement of cutting conditions have also been improved. Moreover, the computer-aided simulation technology of cutting process has also appeared. This technology is of great significance for predicting the temperature and stress of cutting tools and prolonging the service life of cutting tools. The application of casting, stamping, hot pressing and injection molding represents the expansion of the high-speed application range of cast iron, cast steel and alloy steel. In the manufacturing of stamping dies and casting molds, the industrial leading countries spend most of their research and development time on machining and polishing processes. The machining and polishing of stamping die or casting die account for about 2 / 3 of the total processing cost, and high-speed milling can be used to shorten the development cycle and reduce the processing cost.
The reason why high-speed is more and more widely used in industry is that it has significant advantages over traditional processing. Specifically, it has the following characteristics:
（1） The production efficiency is effectively improved.
High speed machining allows a large feed rate, which is 5-10 times higher than that of conventional cutting, and the material removal rate per unit time can be increased by 3-6 times. When a large number of metal parts need to be cut, the processing time can be greatly reduced.
（2） Reduce cutting force by at least 30%.
Due to the extremely shallow cutting depth and narrow cutting width adopted at high speed, the cutting force is small. Compared with conventional cutting, the cutting force can be reduced by at least 30%. This can reduce the machining deformation for parts with poor machining rigidity and make it possible to cut some thin-walled fine workpieces.
（3） The processing quality is improved.
Because the excitation frequency of tool cutting is far from the natural frequency of the process system during high-speed rotation, the forced vibration of the process system will not be caused, and a good machining state is ensured. Because the cutting depth, cutting width and cutting force are very small, the deformation of the tool and the workpiece is small, the dimensional accuracy is maintained, the cutting failure layer is thin, the residual stress is small, and the machining with high accuracy and low roughness is realized.
From the perspective of dynamics, it can be seen that the reduction of cutting force will reduce the amplitude of vibration (i.e., forced vibration) generated by cutting force; The increase of rotation speed makes the working frequency of the cutting system far away from the natural frequency of the machine tool to avoid resonance; Therefore, high speed can greatly reduce the surface roughness and improve the machining quality.
（4） Reduce processing energy consumption and save manufacturing resources.
Due to the high metal removal rate per unit power, low energy consumption and short manufacturing time of workpieces, the utilization rate of energy and equipment is improved, and the proportion of cutting processing in the total resources of the manufacturing system is reduced, which meets the requirements of sustainable development.
（5） The process flow is simplified.
Conventional cutting cannot process quenched materials, and quenching deformation must be manually trimmed or solved by electrical discharge machining. High speed can directly process quenched materials. In many cases, the EDM process can be completely eliminated, eliminating the surface hardening problem caused by EDM, and reducing or eliminating manual finishing.