Effect of Feedstock Properties on Extrusion of High Aspect Ratio Microbi-Lumen Tubes

Abstract The micro-extrusion of feedstock is a promising and emerging technology for manufacturing very high length to thickness aspect ratio metallic microcomponents which are not feasible for conventional metal processing methodologies or commonly used feedstock processing technologies. Extrusion of high aspect ratio microcomponents using metallic feedstock confronts the challenges of achieving a continuous extrusion without any breakage, the geometrical accuracy, surface finish and structural properties for the component which are required for the micro-application, during micro-extrusion process. The type of metallic powder, powder size, type of binder, and binder properties are very decisive in making the extrusion process feasible for the micro-application. The influence of feedstock properties on micro-extrusion of high aspect ratio microcomponents are still unknown in case of micro-extrusion of feedstock. In this research work, the effect of type of feedstock on micro-extrusion is studied by extruding microbi-lumen tubes using biocompatible steel feedstocks AISI316 L and 17-4PH at two different aging states (no aging and 1.5 years aging). The geometrical features of the extruded bi-lumen tubes, surface roughness and structural properties are analyzed using three-dimensional (3D) focus variation microscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The analysis showed that feedstock type affects the feasibility of extrusion and geometrical size to a great extent. An average Sa roughness deviation from 1.73 to 4.57 μm was observed for feedstocks 17-4PH and AISI316 L. The study also confirms that binder properties and aging of the feedstocks also have to be taken into account for maintaining the surface finish and structural properties in case of metallic feedstock extrusion of high aspect ratio bi-lumen tubes.

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Debinding and Presintering of High Aspect Ratio Microbi-Lumen Tubes Produced by Extrusion of 17-4PH Feedstock

Journal of Micro and Nano-Manufacturing ◽

10.1115/1.4046562 ◽

2020 ◽

Vol 8 (2) ◽

Author(s):

Sandeep Kuriakose ◽

Salvatore Cataldo ◽

Paolo Parenti ◽

Massimiliano Annoni

Keyword(s):

Aspect Ratio ◽

Structural Properties ◽

Surface Finish ◽

High Aspect Ratio ◽

Three Dimensional ◽

Processing Technologies ◽

Green State ◽

Aspect Ratios ◽

Recent Developments ◽

Thermal Debinding

Abstract Recent developments have showcased that micro-extrusion of feedstock can be used for manufacturing metallic microbi-lumen tubes with very high length-to-diameter aspect ratios, which are not viable by conventional metal extrusion or commonly used feedstock processing technologies like injection molding or hot pressing. The extrusion of high aspect ratio microcomponents faces the challenge of maintaining the geometrical accuracy, surface finish, and structural properties since the micro-extrusion in green state is followed by debinding and sintering operations, which result in shrinkage and variations in surface finish and structure. The stages of the process chain such as solvent/thermal debinding (TD), to remove the polymeric binder, and presintering (PS), to achieve a mild structural rigidity before the sintering, are of critical importance to achieve the surface and structural properties of high aspect ratio microparts and have not been yet studied in case of micro-extrusion of feedstock. In this study, the effect of debinding and PS on surface and structural properties of bi-lumen tubes processed at different extrusion conditions is discussed. Surface roughness of the tubes is analyzed using three-dimensional microscopy, and structural properties are studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The debinding and PS experiments on extruded microbi-lumen tubes retained very good surfaces integrity without any cracks or defects. The study shows that the interactions of extrusion temperature and extrusion velocity influence the surface finish of the extruded tubes the most. The sintered bi-lumen samples showed a good areal surface finish, Sa of 2.21 μm, which is near to the green state value confirming the suitability of the applied debinding and PS parameters.

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Accelerating ion diffusion with unique three-dimensionally interconnected nanopores for self-membrane high-performance pseudocapacitors

Nanoscale ◽

10.1039/c7nr06234f ◽

2017 ◽

Vol 9 (46) ◽

pp. 18311-18317 ◽

Cited By ~ 5

Author(s):

Yuan Gao ◽

Yuanjing Lin ◽

Zehua Peng ◽

Qingfeng Zhou ◽

Zhiyong Fan

Keyword(s):

Aspect Ratio ◽

Surface Area ◽

Structural Stability ◽

High Aspect Ratio ◽

High Performance ◽

Three Dimensional ◽

Rate Capability ◽

Large Surface Area ◽

Nanoporous Structure ◽

Ion Diffusion

Three-dimensional interconnected nanoporous structure (3-D INPOS) possesses high aspect ratio, large surface area, as well as good structural stability. Profiting from its unique interconnected architecture, the 3-D INPOS pseudocapacitor achieves a largely enhanced capacitance and rate capability.

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Self-ordered nanospike porous alumina fabricated under a new regime by an anodizing process in alkaline media

Scientific Reports ◽

10.1038/s41598-021-86696-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mana Iwai ◽

Tatsuya Kikuchi ◽

Ryosuke O. Suzuki

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Porous Alumina ◽

Three Dimensional ◽

Alkaline Media ◽

Alkaline Electrolyte ◽

Subsequent Formation ◽

Interpore Distance ◽

Wide Range ◽

Ordered Porous

AbstractHigh-aspect ratio ordered nanomaterial arrays exhibit several unique physicochemical and optical properties. Porous anodic aluminum oxide (AAO) is one of the most typical ordered porous structures and can be easily fabricated by applying an electrochemical anodizing process to Al. However, the dimensional and structural controllability of conventional porous AAOs is limited to a narrow range because there are only a few electrolytes that work in this process. Here, we provide a novel anodizing method using an alkaline electrolyte, sodium tetraborate (Na2B4O7), for the fabrication of a high-aspect ratio, self-ordered nanospike porous AAO structure. This self-ordered porous AAO structure possesses a wide range of the interpore distance under a new anodizing regime, and highly ordered porous AAO structures can be fabricated using pre-nanotexturing of Al. The vertical pore walls of porous AAOs have unique nanospikes measuring several tens of nanometers in periodicity, and we demonstrate that AAO can be used as a template for the fabrication of nanomaterials with a large surface area. We also reveal that stable anodizing without the occurrence of oxide burning and the subsequent formation of uniform self-ordered AAO structures can be achieved on complicated three-dimensional substrates.

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High-aspect-ratio structure formation techniques for three-dimensional metal-oxide-semiconductor transistors

Microelectronic Engineering ◽

10.1016/j.mee.2006.01.270 ◽

2006 ◽

Vol 83 (4-9) ◽

pp. 1740-1744 ◽

Cited By ~ 1

Author(s):

Hideo Sunami ◽

Shunpei Matsumura ◽

Koji Yoshikawa ◽

Kiyoshi Okuyama

Keyword(s):

Aspect Ratio ◽

Metal Oxide ◽

Structure Formation ◽

High Aspect Ratio ◽

Three Dimensional ◽

Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

High Aspect Ratio Structure

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High-Aspect-Ratio Copper Via Filling Used for Three-Dimensional Chip Stacking

Journal of The Electrochemical Society ◽

10.1149/1.1572154 ◽

2003 ◽

Vol 150 (6) ◽

pp. G355 ◽

Cited By ~ 111

Author(s):

Jian-Jun Sun ◽

Kazuo Kondo ◽

Takuji Okamura ◽

SeungJin Oh ◽

Manabu Tomisaka ◽

...

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Three Dimensional

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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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Strong and Reversible Adhesion of Interlocked 3D-Microarchitectures

Coatings ◽

10.3390/coatings9010048 ◽

2019 ◽

Vol 9 (1) ◽

pp. 48 ◽

Cited By ~ 1

Author(s):

Minho Seong ◽

Hyun-Ha Park ◽

Insol Hwang ◽

Hoon Eui Jeong

Keyword(s):

Aspect Ratio ◽

Structural Stability ◽

High Aspect Ratio ◽

Three Dimensional ◽

Normal Direction ◽

One Dimensional ◽

Reversible Adhesion ◽

Adhesion Behavior ◽

Organic Nanomaterials ◽

Good Agreement

Diverse physical interlocking devices have recently been developed based on one-dimensional (1D), high-aspect-ratio inorganic and organic nanomaterials. Although these 1D nanomaterial-based interlocking devices can provide reliable and repeatable shear adhesion, their adhesion in the normal direction is typically very weak. In addition, the high-aspect-ratio, slender structures are mechanically less durable. In this study, we demonstrate a highly flexible and robust interlocking system that exhibits strong and reversible adhesion based on physical interlocking between three-dimensional (3D) microscale architectures. The 3D microstructures have protruding tips on their cylindrical stems, which enable tight mechanical binding between the microstructures. Based on the unique 3D architectures, the interlocking adhesives exhibit remarkable adhesion strengths in both the normal and shear directions. In addition, their adhesion is highly reversible due to the robust mechanical and structural stability of the microstructures. An analytical model is proposed to explain the measured adhesion behavior, which is in good agreement with the experimental results.

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