| Titanium alloy blisk is one of the most important parts of aero-engine,but its structure is complex and materials is difficult to machine.In the process of side milling titanium alloy blisk,there are problems of large cutting force,low surface quality and processing efficiency.Its processing quality seriously affects the comprehensive performance of the engine.The reasonable tool structure and cutting parameters can give full play to the cutting performance of the tool,reduce the cutting force,and improve the surface quality and processing efficiency.Therefore,tool design and optimization for side milling titanium alloy blisk are carried out to achieve the purpose of processing blisk with high efficienty and high quality.Firstly,in view of the complex structural characteristics of the titanium alloy blisk,the accessibility and the interference position of the ball end milling tool in the process of side milling channels are analyzed,and the processing area of blisk is planned,which provides the theoretical basis and reference for the simulation processing of blisk.Based on the analysis of the structure and side milling process of blisk,the mathematical models of the section profile of tool circumferential cutting edge are established.The mathematical models of edge lines are established by analyzing the general model of the rotary tool,and the correctness and reliability of the designed tool structure curve are verified.Based on the established mathematical model,the parameter modeling of the ball end milling tool is realized by NX10.0,which provides support for analysis and optimization of tool in the following article.Secondly,the finite element software Third Wave Advantedge is used to optimize the structure of the designed ball end milling tool,and the strength and modal analysis of the optimized tool are carried out to ensure that the tool has enough strength in the cutting process and does not resonate with the machine tool.The NX CAM module is used to simulate the layered side milling of blisk,there is no interference and over cutting during the manufacturing process,which proves the rationality of the tool design and the feasibility of this method.Thirdly,the preparation and inspection of the designed and optimized ball end milling tool is completed.The experimental research on side milling titanium alloy is carried out by using the qualified tool.Taking cutting force,surface roughness and processing efficiency as indicators,multi-objective optimization of cutting parameters is accomplished based on NSGA-II genetic algorithm.Finally,according to the characteristics of side milling titanium alloy blisk,the cutting force,surface roughness and processing efficiency are determined as evaluation indicators.Based on the fuzzy mathematics theory,the two-level integrated fuzzy evaluation model of the tool is established,and the comprehensive performance evaluation of the designed tool is completed.The performance of the designed tool is superior to traditional tools for milling titanium alloys.The research results provide theoretical basis and technical support for high efficient and high quality side milling of titanium alloy blisk. |
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