Heat accumulation between scans during multi-pass cutting of carbon fiber reinforced plastics
Heat accumulation between scans during multi-pass cutting of carbon fiber reinforced plastics
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DOI：
10.1007/s00339-018-1647-9
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发表时间：
2018-02-01
影响因子：
2.7
通讯作者：
Konov, V. I.
中科院分区：
文献类型：
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作者：
Kononenko, T. V.;Freitag, C.;Konov, V. I.
研究了激光多程扫描碳纤维增强塑料（CFRP）表面时扫描热积聚引起的基体蒸发。实验分两种方式进行，即在CFRP切割过程中和在低能量辐照避免碳纤维烧蚀的方式。无烧蚀状态的特征是所有吸收的能量都以热量的形式保留在材料中，而在切削状态下，残余热量的分数是未知的。基于二维（2D）热流的分析模型被施加到预测的临界扫描次数，之后的HAS效应引起的矩阵蒸发区（MEZ）的显着增长。根据该模型，临界扫描次数随着激光功率的增加而呈指数下降，而不依赖于进给速率。结果发现，该模型拟合得很好，在烧蚀的自由制度，其中的热输入是很好地定义和已知的实验数据。在切削制度的测量显着减少在深槽中观察到的扫描的临界数量可能是由于变换的热流的几何形状和预期的增加的余热部分。
Matrix evaporation caused by heat accumulation between scans (HAS) was studied in the case of multi-pass scanning of a laser beam over the surface of carbon fiber reinforced plastic (CFRP). The experiments were performed in two regimes, namely, in the process of CFRP cutting and in the regime of low-fluence irradiation avoiding ablation of carbon fibers. The feature of the ablation-free regime is that all absorbed energy remains in the material as heat, while in the cutting regime the fraction of residual heat is unknown. An analytical model based on two-dimensional (2D) heat flow was applied to predict the critical number of scans, after which the HAS effect causes a distinct growth of the matrix evaporation zone (MEZ). According to the model, the critical number of scans decreases exponentially with increasing laser power, while no dependence on the feed rate is expected. It was found that the model fits well to the experimental data obtained in the ablation-free regime where the heat input is well defined and known. In the cutting regime the measured significant reduction of the critical number of scans observed in deep grooves may be attributed to transformation of the heat flow geometry and to an expected increase of the residual heat fraction.