Nanosecond laser micro machining using an external beam attenuator

2003 ◽  
Author(s):  
Johan Bosman ◽  
Henk Kettelarij ◽  
Corne J.G.M. de Kok
Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel Ehmann

Abstract This experimental work utilizes a newly developed method, curved water jet guided laser micro-machining, to generate micro features on metallic surfaces. During the process, material is removed by a high-power nanosecond laser beam which is transmitted through a high-pressure micro water jet via total internal reflection. To achieve intricate texturing patterns, a secondary motion component is superimposed on the XY motion of the workpiece provided by the motion stage. The secondary motion is generated by deflecting the water jet trajectory by a controllable dielectrophoretic force. The induced secondary motion of the water jet cuts the processing time to one half when generating texture patterns for isotropic wetting as compared to processes with only XY motion. The ability to alter the water jet's trajectory by tens of microns at high frequencies, which is beyond the capability of conventional CNC machines, allows a wide range of different micro patterns to be generated, profoundly increasing the flexibility and efficiency of the process as compared to conventional approaches. As a demonstration, surface textures for isotropic and anisotropic behaviors are generated on stainless steel surfaces. The influence of feature spacing, motion speed (frequency) and texturing patterns on surface wettability are studied.


2004 ◽  
Vol 850 ◽  
Author(s):  
Xianfan Xu

ABSTRACTLaser micro-machining is finding many applications in materials processing and manufacturing. Various laser techniques are being used to fabricate micro-electronics, optics, and medical components. This paper will mainly deal with the fundamental issues involved in laser-matter interaction. Our studies are focused on laser induced thermal and thermomechanical phenomena and phase change mechanisms that determine the materials removal process during laser micro-machining. It is shown that during nanosecond laser machining, explosive phase change could occur, during which the liquid is superheated to close to the thermodynamic critical point, followed by an explosive, homogeneous phase transformation. On the other hand, it is observed in the experiment that the time needed for nucleation during laser induced phase explosion is on the order of one nanosecond. Thus, when a laser with a pulsewidth of the order of picosecond or less is used, it is likely that the material can be heated above the critical point, and another type of phase change, spinodal decomposition is possible. Molecular dynamics studies showed that with the use of a femtosecond laser pulse, it is possible to superheat the material to above the critical point, and spinodal decomposition is the dominant mechanism for materials removal.


Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel F. Ehmann

Abstract This experimental work utilizes a newly developed method, curved water jet guided laser micro-machining, to generate micro features on metallic surfaces. During the process, material is removed by a high-power nanosecond laser beam which is transmitted through a high-pressure micro water jet via total internal reflection. To achieve intricate texturing patterns, a secondary motion component is superimposed on the XY motion of the workpiece provided by the motion stage. The secondary motion is generated by deflecting the water jet trajectory by a controllable dielectrophoretic force. The induced secondary motion of the water jet cuts the processing time to one half when generating texture patterns for isotropic wetting as compared to processes with only XY motion. The ability to alter the water jet’s trajectory by tens of microns at high frequencies, which is beyond the capability of conventional CNC machines, allows a wide range of different micro patterns to be generated, profoundly increasing the flexibility and efficiency of the process as compared to conventional approaches. As a demonstration, surface textures for isotropic and anisotropic behaviors are generated on stainless steel surfaces. The influence of feature spacing, motion speed (frequency) and texturing patterns on surface wettability are studied.


2007 ◽  
Vol 22 (8) ◽  
pp. 970-979 ◽  
Author(s):  
Lu Xu ◽  
Donnacha Lowney ◽  
Patrick J McNally ◽  
A Borowiec ◽  
A Lankinen ◽  
...  

2006 ◽  
Vol 83 (4-9) ◽  
pp. 1400-1402 ◽  
Author(s):  
Sandra Zoppel ◽  
Maria Farsari ◽  
Robert Merz ◽  
Johann Zehetner ◽  
Günther Stangl ◽  
...  

2015 ◽  
Vol 44 (11) ◽  
pp. 1122002
Author(s):  
陈恩果 CHEN En-guo ◽  
黄炳乐 HUANG Bing-le ◽  
徐胜 XU Sheng ◽  
郭太良 GUO Tai-liang

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