Experimental And Applied Study On Profile Milling Process Optimization Of Titannium Alloy Blades

Modern aero engines have complex structure and lots of components,and the blades belong to one of the key components.In order to meet the aerodynamic performance requirements of the part,the inner and back arc surfaces of the blade are designed as complex space surfaces.At the same time,the surface quality requirement of the blade is high,especially the surface roughness and residual stress of the surface layer have strict indexes to meet the requirements of antifatigue and anti-corrosion performance.Titanium alloy has high strength,good corrosion resistance and high temperature resistance.It satisfies the requirements of the working environment of aviation blades for its material properties.It is a typical material for aerospace engine blades,but it is also a common material which is difficult to cut.Domestic blade processing enterprises often trade high process precision and surface quality at the expense of production efficiency when manufacturing titanium alloy blades,resulting in high production costs,which hinders development and international competition strength of the enterprises.The blade milling process is backward in level and relies heavily on imported cutting tools,resulting in high production costs and low profits.For the country and the industry it causes disadvantage in global competition.And it's a bottleneck restricting China's blade manufacturing industry.In view of the above problems,this paper takes the NC milling process of RR84 K titanium alloy as the research object,and carries out the following research work from the perspective of blade machining process optimization:Firstly,basic experiments were carried out on the die forging blank materials of titanium alloy blades,and the elemental composition,hardness and metallographic composition of the materials were obtained.The material tensile test,tribological property test and Hopkinson pressure bar experimental test were carried out,and the key properties such as material strength,elastic modulus,friction coefficient and J-C constitutive equation were obtained,which provides key data support for FEM simulation of titanium alloy cutting,and provides an important basis for optimization of blade profile milling tools and process parameters.3D cutting finite element simulation software was used to simulate the rough surface milling and finishing process of the blade profile.The simulation data of cutting force and cutting temperature were obtained,which provided a reference for the cutting performance evaluation of the blade profile machining tool.The mathematical model of the residual height between the inter-row spacing and the residual height in the feed direction of the blade profile precision milling cutter is established,and the simulation calculation is carried out,which has a guiding role in the structural optimization design of the blade finishing tool and the optimization of the blade profile finishing process parameters.The modal test flow of the blade milling process system is introduced.The related software and hardware are used to obtain the stability domain Lobes diagram of the system,which provides guidance for process parameter optimization and processing parameter matching of cutting tools.The cutting performance of the original RR84 K blade profile rough milling insert was evaluated and optimized.The new tool has better service life and processing efficiency.The original 12-tooth surface finish milling tool was optimized,and the design scheme of the new 16-tooth tool was proposed.The cutting performance of the two tools was compared,and a further improvement plan for the 16-tooth tool was proposed.The new domestic-made 16-tooth tool reduces tool costs while maintaining process quality and efficiency.The effects of feed per tooth and cutting speed on the milling process of titanium alloy with fine-tooth milling cutter were studied by experiments.The conclusions obtained can be used as a reference for optimization of blade machining process parameters.Based on the actual production,the blade profile rough milling margin prediction method is proposed.Based on this,the Production Module process simulation and optimization software is used to optimize the profile roughing process.This method can improve tool life and machining efficiency,has practical application value,and realizes the optimization of blade processing technology from the aspects of processing parameters.The application and verification of the new blade profile roughing tool and the 16-tooth finishing tool have been carried out,which proves that the new tool has advantages in many aspects,and has the application value on the assembly line,which completes the optimization of the blade machining process from the angle of cutting tools,helping companies achieve the goal of reducing costs and increasing efficiency.