(湖南大學(xué) 機(jī)械與汽車工程學(xué)院 汽車車身先進(jìn)設(shè)計(jì)制造國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410082)
摘 要: 建立Al2O3熱壓陶瓷激光輔助切削準(zhǔn)穩(wěn)態(tài)傳熱模型，采用有限差分方法，利用MATLAB軟件，結(jié)合材料的受熱軟化特性，計(jì)算得到工件的溫度場(chǎng)分布，并由此確定不同激光參數(shù)(激光功率、光束移動(dòng)速度和光斑半徑)下的切削深度。模擬計(jì)算發(fā)現(xiàn)工件表面等溫線為卵圓形，橫截面呈拋物線型，縱截面呈對(duì)稱分布形式，而計(jì)算確定工件橫、縱截面1 000 K等溫線所對(duì)應(yīng)的深度值為加工時(shí)合適的切削深度；通過對(duì)比分析發(fā)現(xiàn)：不同參數(shù)下溫度場(chǎng)計(jì)算確定的切削深度值與實(shí)驗(yàn)值較吻合，采用較高的激光功率、較低的激光移動(dòng)速度和工件表面受輻照激光光斑半徑有利于切削區(qū)域材料的充分軟化，從而獲得較大的切削深度。
關(guān)鍵字: Al2O3熱壓陶瓷；激光輔助切削；溫度場(chǎng)；切削深度
（College of Mechanical and Automobile Engineering, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China）
Abstract:A quasi-steady heat conduction model for laser-assisted machining hot-sintered Al2O3 ceramics was established. Based on finite difference method(FDM), temperature field distribution of the workpiece was calculated by means of MATLAB. Considering the softened characteristic of material after being heated, cutting depths under different laser parameters (laser power, beam moving speed and spot radius) were obtained. The simulation results indicate that the isotherms are ovoid on the surface, parabolic in cross-section and symmetrical in longitudinal section. The corresponding softened depth to isotherm of 1 000 K is concerned as the proper cutting depth. The calculated cutting depths are in good agreement with the experimental ones under different parameters. The results show that the cutting depth and material removal rate can be increased by increasing the laser power, decreasing the beam spot radius and reducing the moving speed of laser beam.
Key words: hot-sintered Al2O3 ceramics; laser-assisted machining; temperature field; cutting depth
