Machining Process and Special Tool Design of Titanium Alloy Inner Cavity Cylindrical Surface

At present, the requirements of aerospace products for processing accuracy are continuously increasing, and the number of overall structural parts in the aerospace field is continuously increasing. High-precision thin-walled cavity parts are more and more widely used in the aerospace product industry. The machining accuracy control of the Grade 2 Titanium Tube electrode, especially the machining accuracy control of the servo system, is directly related to the requirements of many performance indicators of the weapon system. Titanium alloy blanks are generally used for such parts, and the material removal rate can reach 85%. At the same time, a significant production feature of this kind of parts is the variety, small batches, and even single-piece production. This structural feature and production method have determined that its manufacturing technology has always been in an unstable state, and processing and manufacturing have always been faced with difficulties such as long processing cycles, high processing costs, and difficult control of processing accuracy.

The material of the spherical ring frame is titanium alloy tc4, which is a single piece and small batch production. These parts are precision machined parts. The external dimension of the part is sφ108mm, and the wall thickness is 4mm. It is a thin-walled and difficult-to-machine material part, and has high requirements for shape and dimensional accuracy. Due to the integral cutting and forming, it is easy to deform during the processing, the material cutting performance is poor, and the part structure is also poor, which brings great difficulties to the processing. Therefore, choosing a reasonable processing method and the correct tool is the key to ensuring processing quality.

The spherical ring frame material is titanium alloy tc4, which is characterized by: poor thermal conductivity of titanium alloy is a metal material with poor thermal conductivity. During cutting, the contact area between chips and the rake face is small, which is particularly easy to cause thermal deformation of thin-walled parts. Tungsten Sputtering Target alloy has low elastic modulus and large elastic deformation. The modulus of elasticity of titanium alloy is 1078mpa (about 1/2 of steel). When cutting, the workpiece near the flank face has a large springback, resulting in a large contact area between the machined face and the flank face. As a result, the geometric dimensions and accuracy of the workpiece are poor, the surface roughness increases, and tool wear increases. Titanium alloy has a higher affinity and higher cutting temperature. During cutting, the titanium chips and the surface to be cut are occluded with the tool material, resulting in serious tool jamming, which is easy to cause tool jamming and wear. Titanium alloy has strong high temperature chemical activity. When the temperature exceeds 600, there is an interstitial solid solution containing oxygen and nitrogen. After the gas is absorbed, the surface hardness of the titanium alloy is obviously improved, which has a strong wear effect on the knife. Therefore, titanium alloy processing tools are required to have high strength, high toughness and high red hardness.