Titanium alloy has high specific strength, good thermal strength, corrosion resistance, and good low temperature performance. Due to the difficult processing characteristics of titanium alloy materials, when using traditional twist drilling process to make holes, it is easy to form thermal damage to the hole wall and there is drilling quality Low, poor wall surface quality and other issues. Helical milling technology is an emerging efficient and high-quality hole-making technology in the field of aviation equipment manufacturing. Compared with the traditional drilling technology, the spiral milling technology has many advantages: the axial force is small; a tool can be used to process holes of different diameters, reducing the type of tool; the chip is discontinuous, the chip removal space is large, and the chip can be discharged better , To reduce the friction of chips and the processed surface, thereby improving the quality of the processed surface; intermittent processing is conducive to tool heat dissipation, can reduce tool wear, extend tool life and so on.

Cut force and cutting temperature are important process parameters in the cutting process, which have an important influence on the hole making accuracy and processing quality of titanium alloy materials. Scholars at home and abroad have done a lot of research on the cutting force and cutting temperature of titanium alloy cutting. As an important method of making holes, spiral milling has also attracted the attention of researchers at home and abroad since its appearance. From the perspective of processing geometry, the milling cutter simultaneously performs revolution, rotation and feed movements during the spiral milling process. There are continuous cutting of the bottom edge and intermittent cutting of the side edge during processing, and its undeformed chip geometry and There is a quantitative relationship between dimensions and cutting parameters. Through the study of the relationship between the milling cutter side edge cutting and the bottom edge cutting removal, it is found that under the condition of the milling cutter shape is fixed, the ratio between the milling cutter side edge cutting removal material and the bottom edge cutting removal material is only related to the tool diameter and processing Depending on the hole diameter, this ratio has a direct impact on the axial cutting force, processing temperature and quality. The temperature rise at any point on the workpiece during the spiral milling process is the result of the simultaneous action of the end-edge cutting heat generation and the side-edge cutting heat generation of the milling cutter. Combining the spiral milling dynamic analysis and heat transfer theory can establish a three-dimensional temperature prediction of the spiral milling hole Model and analyze the cutting temperature characteristics of spiral milling holes. Using the above model to analyze the temperature of the spiral milling hole, it is found that the cutting temperature increases when the spindle speed and the spiral lead increase, and the closer the heat source and the temperature measurement point, the higher the measured temperature.

Experimental study on spiral milling of titanium alloy, analyzed the influence of processing parameters on cutting force and cutting temperature quality, and reached the following main conclusions.

  • (1) During the spiral milling L process, the temperature of the measuring point rises first and then falls due to the mutual influence of heat transfer and heat dissipation. The local temperature curve shows periodic fluctuations, and the fluctuation period is the tool revolution period.
  • (2) F in spiral milling. , E fluctuates periodically with the revolution of the tool, in each cycle, only F. The size and change trend are the same, but there is a phase difference of 900.
  • (3) When the cutting speed increases, the cutting temperature rises significantly, and the cutting force remains basically unchanged; the axial feed per tooth and tangential feed per tooth increase, there is no significant change in cutting temperature, and the cutting force rises. Cutting temperature is the main factor affecting the surface quality of titanium alloy machining holes. The cutting temperature is high, the chip fluidity becomes poor, it is easy to stick to the chip flute and block the tool, reducing the cutting ability of the tool, resulting in a large number of burrs at the exit of the workpiece surface, reducing the quality of the machining hole.
  • (4) Under the premise of ensuring the machining efficiency and machining quality at the same time, it should try to choose a large tangential feed per tooth, a large axial feed per tooth and a low cutting speed.