激光熔蚀内部孔穴形态及相态变化

发布时间：2017-12-27 06:15

  本文关键词：激光熔蚀内部孔穴形态及相态变化　出处：《化工学报》2017年S1期 　论文类型：期刊论文

  更多相关文章： 脉冲激光 内部空穴 相变 分子模拟 微尺度

【摘要】：采用分子动力学方法对皮秒脉冲激光在晶体材料内部熔蚀出空穴的过程进行了模拟研究。通过记录整个烧蚀过程中粒子速度和位置的变化得到了材料形态变化的原子图像;同时,对粒子动能和受力进行统计分析得到了整个材料内部的应力传导和温度变化分布,并利用P-T相图对特定位置处的材料相态变化进行了分析。结果表明:仅处于特定能量密度范围内的皮秒脉冲激光可在晶体材料内部加工出孔穴;激光能量在烧蚀点处的累积以及转化会导致材料内部出现极强的应力波,并且应力的传递将导致烧蚀点处熔池中材料的喷溅与分离,并使材料内部产生结构缺陷;此外,在分析材料内部的温度分布时可以发现激光烧蚀过程中的热影响区极小,并且大部分在加热过程中被破坏的晶格结构在材料冷却后能得到恢复,但晶体材料中仍会存在分散的片状晶格缺陷。
[Abstract]:A molecular dynamics method is used to simulate the cavitation process of a picosecond pulse laser in the crystal material. Recorded by changes in particle position and speed of the ablation process obtained atomic images of morphological changes of the material; at the same time, the particle kinetic energy and stress were analyzed by the entire material internal stress conduction and temperature distribution, and the use of P-T to the specific location of the phase diagram of phase change materials is analyzed. The results showed that: only in the picosecond pulse laser specific energy density range in crystal materials processed inside cavity; laser energy accumulated in the ablation point and the transformation will lead to internal stress of strong wave, transfer and stress will lead to expulsion and separation of the ablation point in the weld pool. And the material internal structure defects; in addition, in the analysis of the temperature distribution inside the material can be found in the heat affected zone of the laser ablation process is extremely small, and most of the lattice structure in the heating process can be recovered in the destruction of the material after cooling, but the crystal materials remain scattered lamellar lattice defects.
【作者单位】： 中国海洋大学工程学院;
【基金】：国家自然科学基金项目(51376164)~~
【分类号】：TN249
【正文快照】： 引言自1960年激光器问世以来,领域内众多学者就对材料受激光点源辐照后产生的变化展开了大量的理论以及实验研究[1-2]。激光加工因其非接触性以及超精细加工能力被广泛地应用于理论研究和工程实践中,部分学者尝试将激光应用于加工微槽道[3-5],这部分研究着重关注了材料被高能，

本文编号：1340574