毫秒激光打孔过程中熔融喷溅物的温度分析
关键词：激光打孔；喷溅物；气化损失
毕业设计说明书（论文）外文摘要
Title the Analysis of Temperature of Melting Spills in the Process of Millisecond Laser Drilling
Abstract
The average temperature of the molten spitting produced in the millisecond laser drilling process were analyzed in this article. First, we introduce the status of the laser drilling experiments and simulation
and the mechanism of the generation of splashes briefly. Starting from experiment, we measured the depth and diameter of the hole when drilling with the laser with radius of 250um, the pulse width of 1ms and different energy. A one-dimensional model was established, and we assumed the mass transfer completely caused by liquid splashing. Based on the steady-state heat conduction theory, we deduced the analytical expressions of drilling speed, and we got the relationships of the average temperature of the liquid splashing and drilling depth. The average temperature of the molten splashes and the loss rate of laser energy by vaporization was determined by numerical calculations. We analyzed the relationship between the average temperature of splashes, the loss rate by vaporization and the energy of laser, and the time required when temperature rises under the effect of laser with different energy. The results showed that when the laser power density becomes larger, the average temperature of the liquid splashing rises, more energy loss by vaporization, and the efficiency of drilling becomes lower.
Keywords: laser drilling; splashes; vaporization loss
目次
1 引言 1
1.1 激光 1
1.2 激光打孔 1
1.3 激光打孔的实验研究 2
1.4 激光打孔模拟研究 2
1.5 熔融喷溅 3
2 毫秒激光金属打孔相关理论 4
2.1 固态阶段 4
2.2 熔融阶段 5
2.3 打孔速度 6
2.4 激光加热的时间 9
2.5 打孔深度 9
2.6 计算参数 10
2.7 重力对物质迁移的影响 11
3 计算及讨论 12
3.1 温度与孔深度的关系 12
3.1.1 抛物线形孔 12
3.1.2 实验打出的孔 14
3.2 不同能量激光打孔实验 16
3.3 计算结果与讨论 17
结论 21