激光加热辅助微细铣削温度场仿真研究

发布时间：2019-06-22 13:31

【摘要】：微细铣削技术具有高度柔性化,加工材料多样化,加工效率高,加工精度高等优点,是微小型零件尤其是复杂结构零件的有效加工方法之一。然而,微细铣削在加工高温合金、结构陶瓷和复合材料等难加工材料过程中,存在刀具磨损严重,加工表面质量差,加工效率低和加工成本高等问题。激光加热辅助加工通过在切削前局部加热待加工材料,降低工件材料的硬度和剪切强度,提高硬脆性材料的延展性,能够有效的改善材料的切削性能。激光加热辅助微细铣削技术将微细铣削和激光加热辅助加工的优点结合起来,通过合理的选择激光参数和切削参数,可以获得较好的加工效果。本文基于有限元软件对脉冲激光加热辅助微细铣削的温度场和微细铣削过程进行仿真研究,分析了激光参数对温度场分布的影响以及温度场分布对微细铣削过程的影响,具体工作如下:(1)分析激光加热过程中激光与工件之间的热交换过程,建立传热模型并利用有限元软件求解。对脉冲光纤激光器热源的光源特性进行分析,建立脉冲激光热源模型。(2)利用温度场有限元仿真模型,分析激光光斑直径、激光扫描速度和单脉冲能量等激光参数对温度场分布的影响。对比分析有限元仿真结果与前期开发的仿真软件计算结果,分析模型简化与计算方法对仿真结果的影响。采用红外热像仪测量激光加热工件的表面温度,结果表明试验值与仿真值变化趋势相同。(3)简化微细铣削过程建立二维切削模型,分析切削变形过程原理以及切削热的产生。针对Ti6Al4V钛合金材料选择合适的仿真参数,对比激光加热辅助微细铣削与微细铣削的仿真结果,最大应力降低了约30%,切深抗力降低了约57%,主切削力降低了约20%,说明激光加热材料能够改善难加工材料的切削性能,仿真结果表明Ti6Al4V钛合金的适宜切削温度为400℃左右。
[Abstract]:Micro milling technology has many advantages, such as high flexibility, diversification of machining materials, high machining efficiency and high machining accuracy. It is one of the effective machining methods for micro parts, especially complex structural parts. However, in the process of machining superalloys, structural ceramics and composites, there are some problems, such as serious tool wear, poor machining surface quality, low machining efficiency and high machining cost. Laser heating assisted machining can effectively improve the cutting performance of the material by heating the material to be machined locally before cutting, reducing the hardness and shear strength of the workpiece material, and improving the extensibility of the hard and brittle material. Laser heating assisted micro milling technology combines the advantages of micro milling and laser heating auxiliary machining, and good machining effect can be obtained by reasonably selecting laser parameters and cutting parameters. In this paper, the temperature field and micro-milling process of pulse laser heating assisted micro-milling are simulated based on finite element software. The influence of laser parameters on temperature field distribution and the influence of temperature field distribution on micro-milling process are analyzed. The concrete work is as follows: (1) the heat exchange process between laser and workpiece in laser heating process is analyzed, and the heat transfer model is established and solved by finite element software. The light source characteristics of pulse fiber laser heat source are analyzed, and the pulse laser heat source model is established. (2) the effects of laser spot diameter, laser scanning speed and monopulse energy on the temperature field distribution are analyzed by using the finite element simulation model of temperature field. The finite element simulation results are compared with those of the previously developed simulation software, and the influence of model simplification and calculation method on the simulation results is analyzed. The surface temperature of laser heated workpiece is measured by infrared thermal imager. The results show that the experimental value is the same as the simulated value. (3) the two-dimensional cutting model is established by simplifying the micro-milling process, and the principle of cutting deformation process and the generation of cutting heat are analyzed. According to the selection of appropriate simulation parameters for Ti6Al4V titanium alloy materials, compared with the simulation results of laser heating assisted micro milling and micro milling, the maximum stress is reduced by about 30%, the cutting depth resistance is reduced by about 57%, and the main cutting force is reduced by about 20%, which indicates that the laser heating material can improve the cutting performance of refractory materials. The simulation results show that the suitable cutting temperature of Ti6Al4V titanium alloy is about 400 鈩，

本文编号：2504627