Research On High Efficiency Machining Of Aerospace Titanium Monolithic Structure Parts And Its Engineering Application

With the rapid development of the aerospace industry, the demand for the monolithic components of the titanium alloy increases rapidly. However, the components have some characteristics difficult to machine, such as high material removal rate, thin-wall and complex shapes. which has brought great challenges in meeting the requirement of high quality and efficiency manufacturing.Based on the Finite Element Analysis and the milling process experimental analysis, the machinability of the monolithic titanium alloy with reinforcing stiffener and complex surface is investigated. The technology planning of the high efficiency machining process for the monolithic components is also studied in the present paper.The main work and results are summarized as follows:(1) The Finite Element Analysis on the milling ability of the titanium alloy and thermo-mechanical coupled model are investigated. This model includes the dynamic failure criteria of the material constitutive model, separation and fracture criteria of the chip, tool-chips-workpiece friction model, ect.. Under the condition of different temperatures and strain rates, the relational model between stress and strain of the titanium alloy is studied. The JC modified constitutive equations for aerospace titanium alloy is also established. According to the simulation results, the cutting force, cutting temperature, chip formation under different tool geometry are analyzed.(2) Experimental research on milling process of the aerospace titanium alloy is conducted. The structure of component, machine performance, processing, installation methods are analyzed to reveal the milling ability of the aerospace titanium alloy under the different milling parameters. The cutting force, cutting temperature, surface roughness, chip formation, tool wear, and the feasible scheme are investigated in order to optimize the cutting process parameters, which promotes the scientific basis for high efficiency machining of the aerospace titanium alloy.(3) The Engineering verification for the monolithic components of rudder skeleton of TC4 titanium alloy is conducted. It is found that, the machining efficiency of the monolithic components of rudder skeleton is promoted remarkably by optimizing process parameters, optimal selecting for cutting tools, optimization of cutting path, and designing special tooling.The results of this investigation can be applied in machining the similar structure components with thin-walled and multi-surfaces.