Al_2O_3陶瓷薄片CO_2连续激光弯曲试验

摘要

脆性材料的激光弯曲成形是激光快速成形技术的重要应用.本文通过改变激光功率、扫描速度等工艺参数,利用CO_2连续激光对氧化铝陶瓷薄片进行了弯曲试验.同时,引入线能量密度来寻求适合弯曲的最佳工艺参数,并结合氧化铝陶瓷的高温性能分析了其激光弯曲特点.试验结果表明:氧化铝陶瓷在温度梯度机制下要实现激光弯曲必须使样品表面达到一定温度以降低其脆性和屈服应力,避免裂纹的产生;采用CO_2连续激光可以对氧化铝陶瓷薄片进行弯曲,弯曲角度可达2°;氧化铝陶瓷的激光弯曲过程具有强烈的温度敏感性,当试样表面温度大于临界温度时,弯曲角度迅速增加;适合弯曲的最佳线能量密度为17～24 J/mm.%As an important application of laser rapid forming,the laser bending technology of brittle materials has broad prospects.In this paper,the experiments on bending of Al_2O_3 ceramic slices with a CO_2 CW-laser are carried out at various laser processing parameters,including laser powers and scanning velocities.Laser linear energy density is introduced to explore the best processing parameters for laser bending,and bending characteristics are briefly analyzed according to the high temperature properties of A1_2O_3 ceramic.Experimental results show that,to realize laser bending for brittle A1_2O_3 at a temperature gradient,the sample surface must be heated to a specified temperature to ruduce its brittleness and yield stress and to avoid generating cracks.Moreover,the Al_2O_3 ceramic slice can be bent by the CO_2 CW-laser,and the bending angle can be as high as 2°.Furthermore,the laser bending processing of A1_2O_3 ceramic slice is strongly sensitive to temperature,and there exists a critical temperature,above which,the bending angle increases greatly.The best range of laser linear energy density for bending A1_2O_3 ceramic is 17～24 J/mm.