Generation of Surfaces with Isotropic and Anisotropic Wetting Properties by Curved Water Jet Guided Laser Micro-Machining

2020 ◽  
Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel Ehmann
Keyword(s):  
Water Jet ◽  
Nanosecond Laser ◽  
Micro Machining ◽  
Metallic Surfaces ◽  
Wetting Properties ◽  
Laser Micro Machining ◽  
Jet Trajectory ◽  
Wide Range ◽  
Secondary Motion ◽  
Motion Speed

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.

Generation of Surfaces With Isotropic and Anisotropic Wetting Properties by Curved Water Jet Guided Laser Micro-Machining

2020 ◽  
Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel F. Ehmann
Keyword(s):  
Water Jet ◽  
Nanosecond Laser ◽  
Micro Machining ◽  
Metallic Surfaces ◽  
Wetting Properties ◽  
Laser Micro Machining ◽  
Jet Trajectory ◽  
Wide Range ◽  
Secondary Motion ◽  
Motion Speed

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.

Texturing of metallic surfaces for superhydrophobicity by water jet guided laser micro-machining

2020 ◽  
Vol 500 ◽  
pp. 144286 ◽  
Author(s):  
Yi Shi ◽  
Zilin Jiang ◽  
Jian Cao ◽  
Kornel F. Ehmann
Keyword(s):  
Water Jet ◽  
Micro Machining ◽  
Metallic Surfaces ◽  
Laser Micro Machining

Nanosecond laser micro machining using an external beam attenuator

2003 ◽  
Author(s):  
Johan Bosman ◽  
Henk Kettelarij ◽  
Corne J.G.M. de Kok
Keyword(s):  
Nanosecond Laser ◽  
External Beam ◽  
Micro Machining ◽  
Laser Micro Machining

Line-Based Laser Induced Plasma Micro-Machining (L-LIPMM)

2013 ◽  
Author(s):  
Rajiv Malhotra ◽  
Ishan Saxena ◽  
Kornel Ehmann ◽  
Jian Cao
Keyword(s):  
Laser Ablation ◽  
Process Parameters ◽  
Ultrashort Pulse ◽  
Experimental Setup ◽  
Micro Machining ◽  
Ultrashort Pulse Laser ◽  
Plasma Generation ◽  
Laser Induced Plasma ◽  
Laser Micro Machining ◽  
Wide Range

Recently, the technique of Spot-based Laser Induced Plasma Micro-Machining (Spot-LIPMM) has been developed to address the limitations of conventional ultrashort pulse laser micro-machining. Its main advantages are adaptability to a wide range of materials and superior wall geometries. We propose a variation of the Spot-LIPMM process by creating line plasma instead of spot plasma, with the use of suitable optics. This paper describes the experimental setup used to create line plasma and the process used for micro-machining with L-LIPMM. Optics simulations are developed as a means of guiding the choice of optics to be used for line plasma generation and estimating the energy and shape of the plasma created. It is shown that this Line-based LIPMM (L-LIPMM) process is capable of micromachining channels at a much higher speed than conventional Spot-based laser ablation or spot-based LIPMM. Additionally, the effects of process parameters on machined geometry using L-LIPMM are discussed.

Phase Change Mechanisms in Pulsed Laser-Matter Interaction

2004 ◽  
Vol 850 ◽  
Author(s):  
Xianfan Xu
Keyword(s):  
Phase Change ◽  
Critical Point ◽  
Spinodal Decomposition ◽  
Nanosecond Laser ◽  
Micro Machining ◽  
Laser Micro Machining ◽  
Thermodynamic Critical Point ◽  
Matter Interaction ◽  
Explosive Phase ◽  
Change Mechanisms

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.

scholarly journals Laser Micro-machining of Three-Dimensional Microstructures in Optical Materials

2009 ◽  
Vol 1179 ◽  
Author(s):  
Xianghua Wang ◽  
Pui To Lai ◽  
Anthony H.W. Choi
Keyword(s):  
Optical Materials ◽  
High Performance ◽  
Cutting Tool ◽  
Three Dimensional ◽  
Micro Machining ◽  
Uv Laser ◽  
Hard Materials ◽  
Laser Micro Machining ◽  
Wide Range ◽  
Convergent Beam

AbstractWe demostrate an advanced precision cutting tool using a 349 nm nanosecond-pulsed UV laser micromachining setup. After expansion and collimation, the laser beam is directed vertically and focused with a high performance triplet lens. With an Al mirror inserted in the path of the convergent beam, the beam can be focused on a horizontal machining plane at any desired tilting angles. Microstructures of a wide range of geometries on hard materials can be formed using this custom machining method. Conventional linear and rotary machining on sapphire materials have been demonstrated.

scholarly journals Generic software tool for counteracting the dynamics effects of optical beam delivery systems

2016 ◽  
Vol 231 (1) ◽  
pp. 48-64 ◽  
Author(s):  
Pavel Penchev ◽  
Stefan Dimov ◽  
Debajyoti Bhaduri ◽  
Sein L Soo ◽  
Benoit Crickboom
Keyword(s):  
Full Range ◽  
Software Tool ◽  
Optical Beam ◽  
Beam Deflection ◽  
Machining Accuracy ◽  
Micro Machining ◽  
Machining Performance ◽  
Laser Micro Machining ◽  
Wide Range ◽  
Functional Features

Laser micro-machining is a promising manufacturing solution for fabricating complex micro-engineering products in wide range of materials that incorporate different multi-scale functional features. Optical beam deflector systems are key components in laser micro-machining systems, and they are one of the main factors determining the processing speed and hence machining throughput. However, their performance is speed dependent and the negative dynamics effects have a direct impact on the laser micro-machining accuracy, repeatability and reproducibility. This article presents a generic software solution for minimising these negative dynamics effects, thus improving significantly the laser machining performance across the full range of available processing speeds. In particular, these improvements are achieved by introducing machine-specific compensations in machining vectors to counteract beam deflectors’ inertia regardless of their directions, length and set process speed. An empirical model was developed to obtain data about the actual dynamic response of the beam deflection system across the full range of available processing speeds, and then based on these data, the proposed generic software was implemented into a stand-alone ‘adaptive’ postprocessor. The generation of machine executable part programs is automated, and it is only necessary for the user to enter the selected scanning speeds and beam diameters. Experimental validation was conducted to demonstrate the capability of the proposed software tool. The results demonstrate that substantial improvements can be obtained in machining quality by maintaining a constant pulse distance throughout the machining operations, while the dimensional accuracy is maintained across the available processing speeds without sacrificing the machining efficiency.

scholarly journals Femtosecond versus nanosecond laser micro-machining of InP: a nondestructive three-dimensional analysis of strain

2007 ◽  
Vol 22 (8) ◽  
pp. 970-979 ◽  
Author(s):  
Lu Xu ◽  
Donnacha Lowney ◽  
Patrick J McNally ◽  
A Borowiec ◽  
A Lankinen ◽  
...  
Keyword(s):  
Dimensional Analysis ◽  
Three Dimensional ◽  
Nanosecond Laser ◽  
Micro Machining ◽  
Laser Micro Machining
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