| As a new processing method in the 20 th century,laser processing is widely used in various industries because of its fast processing speed,small thermal deformation and small heat-affected zone,low processing cost and so on.Compared with traditional machining,it can be effective Reduces the heat affected zone and improves the processing quality.However,traditional laser processing generally blows away the molten material that has reached the melting point under the action of auxiliary gas,and then completes the processing process.In this process,because a large amount of energy input by the laser will be conducted to the inside and surface of the material by heat conduction,resulting in a larger heat affected zone range and more serious ablation phenomenon to reduce the processing quality of the material,a large number of studies have shown The quality is mainly determined by the setting of processing parameters and the temperature field distribution during processing.At the same time,the change of processing parameters also indirectly affects the processing results by changing the temperature field of the material itself.Therefore,it is particularly important to study the change of the temperature field during laser processing.The thesis mainly used water jet assisted laser etching technology to etch 7075 aluminum alloy materials,and set up a temperature field detection system to process different laser parameters and water jet parameters in the process of water jet assisted laser etching.The temperature field in the system is monitored to investigate the change of the temperature field of the 7075 aluminum alloy material by water jet assisted laser etching with different lasers and water jet parameters.Mainly conduct research from the following aspects:(1)Combining domestic and foreign literatures on temperature field monitoring during laser processing,summarize the research status of infrared temperature measurement,CCD temperature measurement,colorimetric temperature measurement and thermocouple contact temperature measurement technology.(2)Analyze the coupling effect among laser,material and water.(3)Mathematical model of temperature field for 7075 aluminum alloy material without water-assisted laser etching and temperature field mathematical model for 7075 aluminum alloy material with water jet assisted laser etching.(4)Using finite element software to simulate the 7075 aluminum alloy material without water-assisted laser etching,the effect of different laser power and laser scanning speed on the temperature field of the material surface is simulated,and the 7075 aluminum alloy material with water jet assisted laser etching At that time,the influence of different water jets and laser parameters on the temperature field on the surface of the material was simulated,and the related influence laws were studied.Different laser and water jet parameters are used to summarize the surface cooling effect of 7075 aluminum alloy material in the process of 7075 aluminum alloy material processed by water jet assisted laser etching,and the water jet and laser parameters corresponding to a better processing result are predicted.(5)The 7075 aluminum alloy material is processed using water jet assisted laser etching processing technology,and the controlled variable experimental research method is used to build a temperature detection system from the side during the laser etching process to assist the anhydrous and water jet assisted laser etching Real-time detection of the surface temperature field of the 7075 aluminum alloy material,the simulation results and experimental results of the surface temperature distribution of the material during the anhydrous auxiliary laser etching process were compared and verified,and the causes of the errors between the two were analyzed,and the water jet assisted laser was studied.The effect of laser parameters and water jet parameters on the cooling effect of the material surface during the etching process,and observation and verification of the better processing results predicted in the foregoing by scanning electron microscope,optical microscope and energy spectrum analyzer.Figure [56] Table [10] Reference [73]... |
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