摘要首先说明了激光与物质相互作用的基本原理以及当今此技术的广泛应用。之后叙述了国内外在激光与物质相互作用课题方面的研究程度和进展,包括:激光打孔的数值模拟研究、实验研究以及激光打孔建立的数学模型。25911
其次,阐述了材料表面受到激光的照射后温度的升高,以及表面材料发生熔融甚至气化现象的基础理论,从而并建立了熔融模型。在后一节中介绍了本文的研究方法:有限差分法。利用了长脉冲激光致金属熔融液体喷溅的理论模型和热传导方程,采用有限差分的方法对长脉冲激光致铝靶热破坏过程进行了数值模拟,并得到了不同输入激光的功率密度对喷溅角度的影响,得出喷溅角度与激光功率密度成反比的结论,同时说明了模拟过程中尚存在的问题。
不同输入激光功率密度对靶材热破坏的程度及对喷溅角度的影响的研究结果为了解毫秒激光与物质相互作用的机理提供了很好的依据,也为实际材料加工应用提供了很好的参考作用。
关键词:毫秒激光、铝靶、热传导方程、有限差分法、温度场、喷溅角度、数值模拟 毕业论文设计说明书外文摘要
Title The ejection angle of molten liquid induce by millisecond pulsed laser
Abstract
Firstly,the basic principle of the interaction between laser and material and wide application of the technology in the current society are described.Next,the research degree and progress of the subject of the interaction between the laser and material at home and abroad were descrobed.Including:laser drilling numerical simulation research,experimental research and the establishment of laser drilling mathematical model.
Secondly,expounds the basic theory of the temperature of the material surface is raised after the laser irradiation,and the basic theory of the melting surface melting and vaporization phenomenon.Thus,the melting model is established. In the later section introduce the research method: finite difference method.Use of the long pulse of laser induced liquid spray of molten metal theory model and the heat conduction,using the finite difference method simulate the thermal damage process of the aluminum target induced by long pulsed laser,and get the influence of different input laser power density on spray angle,lead to the conclusion of the spray angle and the laser power density is inversely proportional.Meanwhile,the problems in the simulation are also explained.
The research results of the different input laser power density effect on the degree of thermal damage of the target and on the spray angle for understanding millisecod laser and material mutual mechanism provides a good basis,it also provides a good reference for the application of real material processing.
Key words:Millisecond laser、Aluminum target、Heat conduction equation、Finite difference method、Temperature field、Spray angle、Numerical simulation
目 次
1 引言 2
1.1研究背景和意义 2
1.2国内外研究进展 3
1.3 本文的主要工作 4
2 毫秒激光致铝熔融及气化的基础理论与研究方法 5
2.1热传导方程 5
2.2关于有限差分法的介绍 6
2.3 物理模型的建立 7
2.3.1一文熔融模型 7
2.3.2二文熔融模型 9
3 毫秒激光致熔融铝靶喷溅角度的研究 13