The Accuracy of Micro-molds Produced by a UV Laser Induced Polymerization

This research work deals with the development of a simple and practical method for manufacturing metallic micromachine parts on the order of 0.01–1.0 mm in size. In this method, an ultraviolet laser beam is irradiated onto the surface of a liquid photopolymer material through a mask. The irradiated pattern is then developed to produce a solidified photopolymer mold. Finally, the metallic part is made by an electroforming process. This paper deals with the first process, the making of the photopolymer mold. At first, the accuracy of the mold is estimated by applying the theories of diffraction and absorption of light. Next, the accuracy is examined experimentally. The results show an accuracy of ± 1 μm can be obtained when a proximity transfer of 10 μm between the mask and the photopolymer surface is used. By stacking thin films, thick and high aspect ratio molds with a reasonably high accuracy are made.

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High quality and high aspect ratio processing of multilayer structures with dissimilar material properties by UV laser microjet

International Congress on Applications of Lasers & Electro-Optics ◽

10.2351/1.5118615 ◽

2016 ◽

Author(s):

Jérémie Diboine ◽

Pierre Leroux ◽

Helgi Diehl ◽

Bernold Richerzhagen

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Material Properties ◽

Dissimilar Material ◽

Multilayer Structures ◽

Uv Laser ◽

High Quality

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Surface Textured Drill Tools—An Effective Approach for Minimizing Chip Evacuation Force and Burr Formation During High Aspect Ratio Machining of Titanium Alloy

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4048432 ◽

2020 ◽

Vol 143 (4) ◽

Author(s):

S. Niketh ◽

G. L. Samuel

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Sliding Friction ◽

Thrust Force ◽

Research Work ◽

Machining Process ◽

Cutting Fluid ◽

Burr Formation ◽

Burr Height ◽

Drill Tool

Abstract The real challenge pertaining to high aspect ratio drilling is the rapid increase in chip evacuation force due to the chip clogging phenomenon occurring at higher drilling depths. The clogged chips will further impede the reachability of cutting fluid at the machining zone leading to the tool temperature buildup. This will eventually result in the catastrophic failure of the tool. Hence, in the present work, an attempt has been made to minimize the chip evacuation force by functionalizing the drill tool surfaces based on the laser microtexturing principle. Microscale textures in the form of circular dimples were created on the flute and margin side of the drill tool with an objective to control the sliding friction, thereby minimizing the chip clogging effect. The effectiveness of the functionalized drill tools were assessed mainly based on the variation in thrust force and torque. Drilling experiments showed a net reduction of 17.18% in thrust force and 26.98% in torque while machining Ti–6Al–4V using the flute and margin textured tool, which justified the effectiveness of micro scale textures in minimizing the chip evacuation forces. The experimental analysis was further extended in terms of burr height evaluation, where FMT tools were found to be highly effective in burr height reduction (1.29 mm), showing a net reduction of 54.26% when compared with the non-textured tool. The outcomes from this research work will be highly beneficial for the manufacturing industries including aerospace, automobile, and spacecraft as high aspect ratio drilling of titanium alloys are still categorized to be the most challenging machining process owing to its lower thermal conductive property.

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Atomic Layer Deposition of GdCoO3 and Gd0.9Ca0.1CoO3

Materials ◽

10.3390/ma13010024 ◽

2019 ◽

Vol 13 (1) ◽

pp. 24

Author(s):

Marion Duparc ◽

Henrik Hovde Sønsteby ◽

Ola Nilsen ◽

Anja Olafsen Sjåstad ◽

Helmer Fjellvåg

Keyword(s):

Thin Films ◽

Aspect Ratio ◽

Atomic Layer Deposition ◽

High Aspect Ratio ◽

High Surface ◽

High Surface Area ◽

Atomic Layer ◽

Oxidation Catalysis ◽

Post Annealing ◽

Layer Deposition

Thin films of the catalytically interesting ternary and quaternary perovskites GdCoO3 and Gd0.9Ca0.1CoO3 are fabricated by atomic layer deposition using metal β-diketonates and ozone as precursors. The resulting thin films are amorphous as deposited and become single-oriented crystalline on LaAlO3(100) and YAlO3(100/010) after post-annealing at 650 °C in air. The crystal orientations of the films are tunable by choice and the orientation of the substrate, mitigated through the interface via solid face epitaxy upon annealing. The films exhibit no sign of Co2+. Additionally, high-aspect-ratio Si(100) substrates were used to document the suitability of the developed process for the preparation of coatings on more complex, high-surface-area structures. We believe that coatings of GdCoO3 and Gd1−xCaxCoO3 may find applications within oxidation catalysis.

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