轻质合金光纤激光切割工艺研究及其回归分析

发布时间：2018-04-14 05:16

本文选题：激光切割 + 切缝形态　；参考：《华中科技大学》2015年硕士论文

【摘要】：随着节能减排和结构轻量化要求的提高,轻质合金(铝合金、钛合金和镁合金)的应用越来越广泛。激光切割具有切割质量好、生产效率高、柔性加工能力强等优点,具有提高轻质合金切割质量的潜力,颇具研究价值。但是,轻质合金激光切割的研究非常有限,其中的工艺特性尚不够明确,有待于加强相关研究。为此,本文系统研究了2mm厚度AA2219铝合金、TC4钛合金和AZ31镁合金的光纤激光切割的工艺特性,取得了以下实验结果:通过工艺试验得到了工艺参数(激光功率、切割速度、离焦量)对铝合金、钛合金、镁合金光纤激光切缝形貌特征(切缝宽度、根部挂渣量和切面粗糙度)的影响规律,并根据试验结果优化了工艺参数。在优化的工艺参数范围内可以得到粗糙度Rz满足一级质量要求的切缝。对三种材料的光纤激光切割进行了回归分析,同时建立了二次模型和指数模型。通过对比分析确定了不同材料激光切割回归分析的适配模型。结果表明,铝合金激光切割采用二次模型进行回归分析能获得更高预测精度;钛合金激光切割采用指数模型进行回归分析能够获得更高的预测精度;镁合金激光切割在切缝宽度和挂渣量回归分析采用二次模型能够获得更高的预测精度,但是在粗糙度回归分析中,采用指数模型能够获得更高的预测精度。铝合金、钛合金和镁合金光纤激光切缝形态存在共性特征,所有切面都由三个具有不同条纹形貌的特征区域组成,分别为上部平滑横条纹区,中部纵条纹区和下部粗糙斜条纹区。这一共性特征是由激光切割自身的工艺特性所决定。三种条纹区的形成取决于切缝内高压气流和熔池内其他作用力的相互作用。三种材料切缝在粗糙度、挂渣量等细节上的差异则由材料特性的差异所造成。
[Abstract]:With the improvement of energy saving and structural lightweight requirements, the application of light alloys (aluminum, titanium and magnesium alloys) is becoming more and more extensive.Laser cutting has the advantages of good cutting quality, high production efficiency, strong flexible machining ability, and has the potential to improve the cutting quality of light alloy.However, the research on laser cutting of light alloy is very limited, and the technological characteristics are not clear enough.Therefore, the technological characteristics of optical fiber laser cutting of 2mm thickness AA2219 aluminum alloy TC4 titanium alloy and AZ31 magnesium alloy are systematically studied in this paper. The following experimental results are obtained: the process parameters (laser power, cutting speed) are obtained through the process test.The influence of defocus on the morphology of laser cutting of aluminum alloy, titanium alloy and magnesium alloy fiber (cutting seam width, slagging at the root and cutting surface roughness) was studied. The process parameters were optimized according to the experimental results.In the range of optimized process parameters, the roughness Rz can be obtained to meet the quality requirements of the first cut.The regression analysis of fiber laser cutting of three kinds of materials is carried out, and the quadratic model and exponential model are established at the same time.The fitting model of laser cutting regression analysis for different materials was established by comparative analysis.The results show that the regression analysis of laser cutting for aluminum alloy can obtain higher prediction accuracy, and the exponential model for laser cutting of titanium alloy can obtain higher prediction accuracy.In the regression analysis of cutting seam width and slagging amount of magnesium alloy laser cutting, the quadratic model can obtain higher prediction accuracy, but in the roughness regression analysis, the exponential model can obtain higher prediction accuracy.The laser cutting patterns of aluminum alloy, titanium alloy and magnesium alloy fiber have common characteristics. All the sections are composed of three characteristic regions with different stripe morphology, which are the upper smooth transverse stripe region.The middle longitudinal stripe and the lower coarse oblique stripe.This common feature is determined by the technological characteristics of laser cutting itself.The formation of the three stripes depends on the interaction between the high pressure airflow in the slit and the other forces in the molten pool.The differences in the roughness, slagging amount and other details of the three materials are caused by the difference of the material characteristics.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253;TN249

【相似文献】