Optical tracking of the three-dimensional position of an ablative focused laser beam

2003 ◽  
Author(s):  
Steven C. Gebhart ◽  
Robert L. Galloway, Jr. ◽  
E. Duco Jansen
Keyword(s):  
Laser Beam ◽  
Three Dimensional ◽  
Optical Tracking

Dynamic, three-dimensional optical tracking of an ablative laser beam

2005 ◽  
Vol 32 (1) ◽  
pp. 209-220 ◽  
Author(s):  
Steven C. Gebhart ◽  
E. Duco Jansen ◽  
Robert L. Galloway
Keyword(s):  
Laser Beam ◽  
Three Dimensional ◽  
Optical Tracking ◽  
Ablative Laser

Dynamic three-dimensional optical tracking of an ablative laser beam

2003 ◽  
Author(s):  
Steven C. Gebhart ◽  
Robert L. Galloway, Jr. ◽  
E. Duco Jansen
Keyword(s):  
Laser Beam ◽  
Three Dimensional ◽  
Optical Tracking ◽  
Ablative Laser

scholarly journals A critical look at the prediction of the temperature field around a laser-induced melt pool on metallic substrates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi Shu ◽  
Daniel Galles ◽  
Ottman A. Tertuliano ◽  
Brandon A. McWilliams ◽  
Nancy Yang ◽  
...  
Keyword(s):  
Laser Beam ◽  
Constant Velocity ◽  
Three Dimensional ◽  
Laser Beams ◽  
Poor Control ◽  
Metallic Substrates ◽  
Melt Pool ◽  
Mechanical Models ◽  
Transport Effects ◽  
Thermal Histories

AbstractThe study of microstructure evolution in additive manufacturing of metals would be aided by knowing the thermal history. Since temperature measurements beneath the surface are difficult, estimates are obtained from computational thermo-mechanical models calibrated against traces left in the sample revealed after etching, such as the trace of the melt pool boundary. Here we examine the question of how reliable thermal histories computed from a model that reproduces the melt pool trace are. To this end, we perform experiments in which one of two different laser beams moves with constant velocity and power over a substrate of 17-4PH SS or Ti-6Al-4V, with low enough power to avoid generating a keyhole. We find that thermal histories appear to be reliably computed provided that (a) the power density distribution of the laser beam over the substrate is well characterized, and (b) convective heat transport effects are accounted for. Poor control of the laser beam leads to potentially multiple three-dimensional melt pool shapes compatible with the melt pool trace, and therefore to multiple potential thermal histories. Ignoring convective effects leads to results that are inconsistent with experiments, even for the mild melt pools here.

Laser Beam Steering Along Three-Dimensional Paths

2018 ◽  
Vol 23 (3) ◽  
pp. 1148-1158 ◽  
Author(s):  
Brahim Tamadazte ◽  
Rupert Renevier ◽  
Jean-Antoine Seon ◽  
Andrey V. Kudryavtsev ◽  
Nicolas Andreff
Keyword(s):  
Laser Beam ◽  
Beam Steering ◽  
Three Dimensional

Three-dimensional optical trajectory tracing and energy deposition of a laser beam in a laser-driven fusion

2001 ◽  
Vol 63 (3) ◽  
Author(s):  
Shi-Bing Liu ◽  
Ping-Qing Luo ◽  
Yong-Hui Zhang ◽  
Shao-Ping Zhu ◽  
Wei-Yan Zhang
Keyword(s):  
Laser Beam ◽  
Energy Deposition ◽  
Three Dimensional

Three-dimensional numerical investigations of the laser-beam interactions in an undulator

2011 ◽  
Vol 35 (3) ◽  
pp. 308-312 ◽  
Author(s):  
Hai-Xiao Deng ◽  
Tang-Yu Lin ◽  
Jun Yan ◽  
Dong Wang ◽  
Zhi-Min Dai
Keyword(s):  
Laser Beam ◽  
Three Dimensional ◽  
Numerical Investigations

Development of a Diagnosis Method of a Gear Tooth Surface by Predicting Laser Beam Reflection

2013 ◽  
Author(s):  
Eiichirou Tanaka ◽  
Yuta Kojima ◽  
Hiroki Yoshimi ◽  
Kazunari Okabe ◽  
Hitoshi Takebe ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Laser Beam ◽  
Normal Condition ◽  
Gear Tooth ◽  
Three Dimensional ◽  
Measured Data ◽  
Basic Data ◽  
Tooth Surface ◽  
Laser Sensor ◽  
Diagnosis Method

We developed a new diagnostic method by using a laser beam. This method is as follows: A tooth surface is irradiated by the zonal laser beam from an oblique direction, and then the irradiated laser beam line is shifted along the surface of the tooth according to gear rotation. If the damage on the irradiated tooth surface exists, the voltage proportional to laser reflection increases. We developed the method to predict and make the reflection benchmark on the normal condition according to the gear surface. To make the benchmark of the diagnosis, the three dimensional basic-data map (x: irradiated angle, y: irradiated distance, z: reflection intensity) was created by measuring the gear only whose material, heat treatment, and roughness were same as the targeted gear. By using the equations of tooth profile and fillet curves calculated from the specifications of the targeted gear, the distance and angle relations between the laser sensor and the tooth surface can be derived. By using the three dimensional basic-data map, the benchmark can be created. The measured reflection data of the non-damage gear agreed well with the benchmark, therefore we can diagnose the various specification gears, if the targeted gear’s material, heat treatment, and roughness are same. Finally, by using the benchmark which was made by our developed method, we proposed a novel diagnosis method. The procedure of the method is as follows: 1) The benchmark is made from the targeted gear’s specifications. 2) To take into account the fluctuation of the benchmark line influenced by the roughness on the gear surface, normal condition area of the reflected data is defined in the range between −0.05 V and +0.05 V of the benchmark line. 3) The normal condition area and measured data is compared, if the measured data is deviated from the normal condition area, there is defined as the abnormal area possible to be damaged. To confirm the validity of this diagnosis method, the measured value of the damage area with caliper directly and calculated value from the method as mentioned above. The errors of the area and the location were within 20 %. Therefore, the effectiveness of the method using the benchmark data can be confirmed.

Characterization of “Bulk Lithography” Process for Fabrication of Three-Dimensional Microstructures

2013 ◽  
Vol 1 (4) ◽  
Author(s):  
Prasanna Gandhi ◽  
Kiran Bhole
Keyword(s):  
Laser Beam ◽  
Spatial Variation ◽  
Three Dimensional ◽  
Single Layer ◽  
Exposure Dose ◽  
Laser Exposure ◽  
Experimental Characterization ◽  
Gaussian Laser Beam ◽  
Lithography Process

Various ways of fabricating a three-dimensional (3D) component in a single-layer exposure using spatial variation of exposure dose have been presented in the literature. While some of them are based on dynamic mask process, more recently, a process based on varying intensity of a scanning Gaussian laser beam termed as “bulk lithography” has been proposed. In bulk lithography, the entire varying depth 3D microstructure gets fabricated because of spatial variation of intensity of laser imposed at every point in single layer scan. For the bulk lithography process, this paper first presents experimental characterization of unconstrained depth photopolymerization of resin upon exposure to Gaussian laser beam. Experimental characterization carried out for two resins systems: namely 1,6 hexane diol-diacrylate (HDDA) and trimethylolpropane triacrylate (TMPTA), over relatively wider range of Ar+ laser exposure dose and time, show behavior well beyond Beer–Lambert law. A unified empirical model is proposed to represent the nondimensional depth variation with respect to the time and energy of exposure for both resins. Finally, using these models, successful fabrication of several microstructures including micro-Fresnel lens, textured curved surface, otherwise difficult or impossible to fabricate, is demonstrated. Several advantages of the bulk lithography as compared to other similar processes in the literature are highlighted.

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