A PHASE CONJUGATE Nd:YAG LASER WITH BEAM STEERING

1993 ◽  
Vol 02 (02) ◽  
pp. 229-245 ◽  
Author(s):  
F. DIZIER ◽  
J.-L. AYRAL ◽  
J. MONTEL ◽  
J.-P. HUIGNARD
Keyword(s):  
Nd:Yag Laser ◽  
Beam Steering ◽  
High Energy ◽  
Laser Source ◽  
Access Time ◽  
Nitrogen Gas ◽  
Phase Conjugate ◽  
Competitive Effects ◽  
Energy Beam ◽  
The Stability

We analyse the competitive effects which alter the stability of SBS phase conjugate mirrors when the laser operates at repetition rates between 10 and 30 Hz. Satisfactory results are obtained with nitrogen gas cell at 180 Atm. We also propose and experimentally demonstrate a SBS phase-conjugate Nd:YAG laser source with a beam steering function. The laser, designed as an oscillator-amplifier configuration, incorporates a TeO 2 acousto-optic deflector on the low energy beam. The high energy beam (100–185 mJ) is thus deflected over 2.7° and 40 resolved beam directions are obtained with 5 µs access time.

Phase-conjugate Nd:YAG laser with internal acousto-optic beam steering

1991 ◽  
Vol 16 (16) ◽  
pp. 1225 ◽  
Author(s):  
J.-L. Ayral ◽  
J. Montel ◽  
T. Verny ◽  
J.-P. Huignard
Keyword(s):  
Nd:Yag Laser ◽  
Beam Steering ◽  
Phase Conjugate

Microstructure and Mechanical Properties of Nd:YAG Laser Welded Invar 36 Alloy

2011 ◽  
Vol 675-677 ◽  
pp. 739-742 ◽  
Author(s):  
Yue Zhao ◽  
Ai Ping Wu ◽  
Wei Yao ◽  
Zhi Min Wang ◽  
Yutaka S. Sato ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Welding ◽  
Nd:Yag Laser ◽  
Arc Welding ◽  
Welding Process ◽  
High Energy ◽  
High Susceptibility ◽  
Energy Beam ◽  
Microstructure And Mechanical Properties ◽  
And Storage

Invar 36 alloy is increasingly used as a structural material for manufacture of liquefied natural gas (LNG) transporters and storage tanks. However, the conventional arc welding of Invar 36 alloy has high susceptibility of hot-cracking. As a high-energy-beam welding process, laser welding could be effective for producing defect-free Invar 36 weld. In the present study, defect-free Invar 36 weld was successfully produced by Nd:YAG laser welding. The microstructure and mechanical properties of weld were also tested.

Characterization of thermal barrier coatings formed by electon-beam physical vapor deposition (EB-PVD)

1989 ◽  
Vol 47 ◽  
pp. 426-427
Author(s):  
Ozer Unal
Keyword(s):  
Thermal Barrier Coatings ◽  
Physical Vapor Deposition ◽  
Ceramic Coating ◽  
High Vacuum ◽  
Ceramic Coatings ◽  
High Energy ◽  
Thermal Barrier ◽  
Protective Oxide ◽  
Barrier Coatings ◽  
Energy Beam

Interest in ceramics as thermal barrier coatings for hot components of turbine engines has increased rapidly over the last decade. The primary reason for this is the significant reduction in heat load and increased chemical inertness against corrosive species with the ceramic coating materials. Among other candidates, partially-stabilized zirconia is the focus of attention mainly because ot its low thermal conductivity and high thermal expansion coefficient.The coatings were made by Garrett Turbine Engine Company. Ni-base super-alloy was used as the substrate and later a bond-coating with high Al activity was formed over it. The ceramic coatings, with a thickness of about 50 μm, were formed by EB-PVD in a high-vacuum chamber by heating the target material (ZrO2-20 w/0 Y2O3) above its evaporation temperaturef >3500 °C) with a high-energy beam and condensing the resulting vapor onto a rotating heated substrate. A heat treatment in an oxidizing environment was performed later on to form a protective oxide layer to improve the adhesion between the ceramic coating and substrate. Bulk samples were studied by utilizing a Scintag diffractometer and a JEOL JXA-840 SEM; examinations of cross-sectional thin-films of the interface region were performed in a Philips CM 30 TEM operating at 300 kV and for chemical analysis a KEVEX X-ray spectrometer (EDS) was used.

The promises and perfidy of cryomicroscopy and analysis

1994 ◽  
Vol 52 ◽  
pp. 382-383
Author(s):  
Patrick Echlin
Keyword(s):  
Low Temperature ◽  
High Energy ◽  
Short Paper ◽  
List Type ◽  
Time Resolved ◽  
Energy Beam ◽  
Cellular Analysis ◽  
Dissolved Ions ◽  
Embedding Medium ◽  
Low Temperature Microscopy

The unusual title of this short paper and its accompanying tutorial is deliberate, because the intent is to investigate the effectiveness of low temperature microscopy and analysis as one of the more significant elements of the less interventionist procedures we can use to prepare, examine and analyse hydrated and organic materials in high energy beam instruments. The promises offered by all these procedures are well rehearsed and the litany of petitions and responses may be enunciated in the following mantra.Vitrified water can form the perfect embedding medium for bio-organic samples.Frozen samples provide an important, but not exclusive, milieu for the in situ sub-cellular analysis of the dissolved ions and electrolytes whose activities are central to living processes.The rapid conversion of liquids to solids provides a means of arresting dynamic processes and permits resolution of the time resolved interactions between water and suspended and dissolved materials.The low temperature environment necessary for cryomicroscopy and analysis, diminish, but alas do not prevent, the deleterious side effects of ionizing radiation.Sample contamination is virtually eliminated.

Fabrication of circular cooling channels by cold metal transfer based wire and arc additive manufacturing

2021 ◽  
pp. 095440542199561
Author(s):  
Shaohua Han ◽  
Zhongzhong Zhang ◽  
Pengxiang Ruan ◽  
Shiwen Cheng ◽  
Dingqi Xue
Keyword(s):  
Additive Manufacturing ◽  
High Energy ◽  
Cooling Effect ◽  
High Deposition Rate ◽  
Cooling Channel ◽  
Conformal Cooling Channel ◽  
Conformal Cooling ◽  
Energy Beam ◽  
Cooling Channels ◽  
Straight Line

Additive manufacturing has been proven to be a promising technology for fabricating high-performance dies, molds, and conformal cooling channels. As one of the manufacturing methods, wire and arc additive manufacturing displays unique advantages of low cost and high deposition rate that are better than other high energy beam-based ones. This paper presents a preliminary study of fabricating integrated cooling channels by CMT-based wire and arc additive manufacturing process. The deposition strategies for fabricating circular cross-sectional cooling channels both in conformal and straight-line patterns have been investigated. It included optimizing the welding torch angle, fabricating the enclosed semicircle structure and predicting the collision between the torch and constructed part. The cooling effect test was also conducted on both the conformal cooling channel and straight-line cooling channel. The results affirmed a higher cooling efficiency and better uniform cooling effect of the conformal cooling channel than straight-line cooling channel.

A topologically connected multistrip crystal for efficient steering of high-energy beam

2012 ◽  
Vol 7 (04) ◽  
pp. P04002-P04002 ◽  
Author(s):  
E Bagli ◽  
L Bandiera ◽  
P Dalpiaz ◽  
V Guidi ◽  
A Mazzolari ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Beam ◽  
High Energy Beam

A Nonsaturable High‐Energy Beam Monitor

1955 ◽  
Vol 26 (2) ◽  
pp. 229-231 ◽  
Author(s):  
G. W. Tautfest ◽  
H. R. Fechter
Keyword(s):  
High Energy ◽  
Energy Beam ◽  
Beam Monitor ◽  
High Energy Beam

Influence of Nd:YAG Laser Irradiation on an Adhesive Restorative Procedure

2006 ◽  
Vol 31 (5) ◽  
pp. 604-609 ◽  
Author(s):  
M. Franke ◽  
A. W. Taylor ◽  
A. Lago ◽  
M. C. Fredel
Keyword(s):  
Statistical Analysis ◽  
Bond Strength ◽  
Laser Irradiation ◽  
Significant Influence ◽  
Nd:Yag Laser ◽  
Deleterious Effect ◽  
Adhesive System ◽  
High Energy ◽  
Low Energy ◽  
Adhesive Penetration

Clinical Relevance Statistical analysis of the results obtained in this study shows that Nd:YAG laser irradiation on the adhesive system has a significant influence on bond strength to dentin. Bond strength is improved by better adhesive penetration when low energy is applied; whereas, high energy densities have a deleterious effect on the procedure.

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