Research On Plunge Milling Tools Based On Chip-splitting Principle

Manufacturing industry is the foundation of the national economy,the ability to master advanced basic processes is one of the characteristics that reflects the level of manufacturing ability of a country.As a processing technology with efficiency advantage,plunge milling has a great potential in the processing field of integral impellers and blisks which use stainless steel,titanium alloys and high-temperature alloys as common materials.In addition,plunge milling process has a great value in the fields like mold processing,which need to remove a large amount of material efficiently.Currently,due to the lack of high-performance,low-cost,standardized plunge-cutting tools,the plunge milling process has not been widely used.In this context,this study proposes the idea of applying chip-splitting principle,which can improve the tool performance effectively,to the design of plunge milling tools.The analysis of various tool structures which can achieve chip-splitting indicates that insertdislocation chip-splitting principle and wave edge insert chip-splitting principle are suitable for designing plunge milling tools.Furthermore,a mathematical model was established to describe the relationship between the allowable feed per-tooth and the geometric parameters of the tool.This model has an important value for tool designers and users.According to the application situation and the cutting force characteristics of the tool,the high-strength alloy steel,42 CrMo,is selected as the material of the tool body,the carbide alloy with PVD coat is selected as the material of the insert.The plunge milling tool is designed as an indexable structure,and the reasonable setting range of the tool angle is briefly analyzed.Combined with the structural features of the tool,the machining process is designed and continuously optimized,the qualified plunge milling tool is finally manufactured.Based on a lot of cutting experiments which take the ordinary plunge milling tools as the comparison,the analysis of cutting force,cutting vibration and tool wear can prove that the application of insert-dislocation chip-splitting principle can reduce the cutting force and increase the tool life.Moreover,the smaller cutting force generated by the insert-dislocation tool can make up for the disadvantage of having a small number of equivalent teeth.That is,the level of cutting vibration caused by the insert-dislocation tool is not significantly higher than that of ordinary tool.Besides,the application of the wave edge insert chip-splitting principle can significantly reduce the cutting force and has a greater effect on the improvement of tool performance.However,due to the limited time and effort,the influence of the application of the wave edge insert chipsplitting principle on cutting vibration and tool life will be analyzed in future studies.The flow channel of the integral impeller is a typical deep groove structure and a large amount of material needs to be removed during the rough machining process.Besides,the integral impeller is made of hard-to-process materials such as stainless steel and titanium alloy.Hence,the processing is difficult and really takes too much time.The insert-dislocation tool has been successfully tested at the roughing process of flow channel of the integral impeller.