激光致等离子体冲击波对小孔内物质迁移的作用机理
关键词 激光打孔 等离子体冲击波 物质迁移
毕业论文设计说明书外文摘要
Title The Mechanism Research of the Effect of the Plasma Stock Wave Caused by Laser on the Matter Migration in the Holes
Abstract
In millisecond laser drilling,holes are easily being blocked up, the plasma stock wave produced by the nanosecond laser is being used to promote the transformation of molten material.The mechanism of the shock wave about material migration is being studied in this thesis.Through experiments of laser processing under different conditions ,getting the relationship between laser energy,viscosity, holes depth with the matter migration rate,and working out the proper viscosity of liquids to imitate the molten aluminum by computation. The results show thatwith laser energy increasing,the migration increases;with hole depth increasing,the migration reduces;with liquid viscosity increasing,the migration reduces on the general trend.These results contributes to the further study on the impact of the plasma stock wave caused by laser on the matter migration during laser processing.
Keywords laser drilling plasma stock wave matter migration
目 次
1 引言 1
1.1 研究背景 1
1.2 毫秒激光打孔与纳秒激光加工 1
1.2.1 毫秒激光打孔过程 1
1.2.2 纳秒激光加工 3
1.3 激光与物质相互作用 4
1.3.1 短脉冲激光与物质作用形成等离子体原理 4
1.3.2 激光与物质作用时的反冲压力 5
1.3.3 等离子体冲击波机制 6
1.4 本文的主要工作 6
2 激光致等离子体冲击波对小孔内物质迁移率的影响 8
2.1 液态铝的模拟机理 8
2.2 实验过程 9
2.2.1 铝材小孔预制 9
2.2.2 液体粘度的调制 10
2.2.3 表面张力的测量 11
2.2.4 实验光路 12
2.2.5 等离子体冲击波对水介质的迁移作用实验 12
2.2.6 等离子体冲击波对不同粘度液体介质的迁移作用实验 16
3 小孔内物质迁移率的实验结果分析 19
3.1 等离子体冲击波对介质的迁移作用中激光能量的影响 19
3.2 等离子体冲击波对介质的迁移作用中孔深的影响 20
3.3 等离子体冲击波对介质的迁移作用中液体粘度的影响 21
结 论 24
致 谢 25