Processing of Nanoporous Gold by Dealloying and its Morphological Control

2007 ◽  
Vol 561-565 ◽  
pp. 1657-1660 ◽  
Author(s):  
Masataka Hakamada ◽  
Mamoru Mabuchi
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Acid Treatment ◽  
Nanoporous Gold ◽  
Anisotropic Structure ◽  
Ideal Strength ◽  
Pore Characteristics ◽  
Very High ◽  
Ligament Size ◽  
The Ideal

Nanoporous gold was fabricated by dealloying and their pore characteristics were further modified by thermal or acid treatment. The fabricated nanoporous gold had a ligament size of approximately 5 nm. Thermal treatment on the nanoporous gold increased the ligament size to approximately 500 nm. During the thermal treatment, ligaments are bonded across the cracks which had been generated during the dealloying. Acid treatment also increased the ligament size to approximately 500 nm; however, the acid treatment had a different effect on the pore characteristics from the thermal treatment. As a result, nanoporous gold prism microassembly with anisotropic structure was spontaneously fabricated by the acid treatment. The mechanical properties of nanoporous gold were also examined. It is estimated that the yield strength of nanosized ligaments in nanoporous gold is very high and close to the ideal strength of gold.

scholarly journals Pore and ligament size control, thermal stability and mechanical properties of nanoporous single crystals of gold

Nanoscale ◽  
2017 ◽  
Vol 9 (38) ◽  
pp. 14458-14466 ◽  
Author(s):  
Maria Koifman Khristosov ◽  
Shiri Dishon ◽  
Imrit Noi ◽  
Alex Katsman ◽  
Boaz Pokroy
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Single Crystals ◽  
Size Control ◽  
Nanoporous Gold ◽  
Ligament Size

Thermal stability and mechanical properties investigation of nanoporous gold single crystals.

The mechanical properties of perfect crystals I. The ideal strength

1972 ◽  
Vol 330 (1582) ◽  
pp. 291-308 ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Sodium Chloride ◽  
Room Temperature ◽  
Cleavage Plane ◽  
Ideal Strength ◽  
Lennard Jones ◽  
Computer Calculations ◽  
The Ideal

In this paper we present computer calculations of the ideal strength of crystals of sodium chloride and argon, for a variety of modes of homogeneous deformation. As models of the interatomic binding we employ the simple, two-body, central-force Born-Mayer and Lennard-Jones potentials respectively. The calculations for argon are appropriate to absolute zero, those for sodium chloride to room temperature. The results indicate a very marked anisotropy of the ideal tensile strength for sodium chloride, with a pronounced minimum at <100>, which is consistent with the observed cleavage on this plane. The ideal tensile strength of argon is shown to be much less dependent on orientation, which accords with the lack of any obvious cleavage plane in this material. We also make some estimates of the ideal shear strength, and find this to be a minimum for {111} <112> shear for both argon and sodium chloride.

scholarly journals A Study on Different Bandwidths and Rim Decorations’ Influence on the Mechanical Properties of Graphene Nanoribbon

2021 ◽  
Vol 2083 (2) ◽  
pp. 022108
Author(s):  
Guo Ziliang
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Graphene Nanoribbons ◽  
Graphene Nanoribbon ◽  
First Principle ◽  
Ideal Strength ◽  
The Future ◽  
The Ideal

Abstract This paper structured the Graphene Nanoribbon with different bandwidths and rim decorations and obtained the ideal strength and modulus of elasticity based on the calculation under the First Principle. It can be known that the mechanical properties of Graphene Nanoribbon are close to that of graphene, which have less changes with different bandwidth. However, the mechanical properties would be influenced by different decorations which may change the electronic connection state of edge carbon atoms. The results found in this paper can provide some reference for researchers to study the mechanical properties of graphene nanoribbons in the future.

UNS A97075

Alloy Digest ◽  
1986 ◽  
Vol 35 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Temperature Performance ◽  
Structural Applications ◽  
Structural Parts ◽  
Very High

Abstract UNS No. A97075 is a wrought precipitation-hardenable aluminum alloy. It has excellent mechanical properties, workability and response to heat treatment and refrigeration. Its typical uses comprise aircraft structural parts and other highly stressed structural applications where very high strength and good resistance to corrosion are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low temperature performance as well as forming, heat treating, and machining. Filing Code: Al-269. Producer or source: Various aluminum companies.

KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽  
2000 ◽  
Vol 49 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Heat Treating ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Kaiser Aluminum ◽  
Structural Parts ◽  
Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

TIMKEN 16-15-6

Alloy Digest ◽  
1963 ◽  
Vol 12 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Creep Resistance ◽  
Elevated Temperatures ◽  
Roller Bearing ◽  
Heat Treating ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Corrosion And Oxidation ◽  
Very High ◽  
High Creep Resistance

Abstract Timken 16-15-6 is a non-magnetic, austenitic, corrosion and heat resistant steel having high creep resistance at elevated temperatures and good corrosion and oxidation resistance. It age-hardens at elevated temperatures after solution quenching, and possesses very high mechanical properties. This datasheet provides information on composition, microstructure, hardness, and tensile properties as well as creep. It also includes information on forming, heat treating, machining, and joining. Filing Code: SS-150. Producer or source: Timken Roller Bearing Company.

The Influence of Isothermal Annealing and Structural Defects on Properties of Amorphous Fe78Si11B11 with High Magnetization Saturation

2017 ◽  
Vol 68 (3) ◽  
pp. 478-482 ◽  
Author(s):  
Katarzyna Bloch
Keyword(s):  
Numerical Analysis ◽  
Thermal Treatment ◽  
Saturation Magnetization ◽  
Isothermal Annealing ◽  
Diffusion Processes ◽  
Structural Defects ◽  
High Saturation Magnetization ◽  
Magnetization Curves ◽  
Magnetization Saturation ◽  
Very High

This paper presents the results of numerical analysis of the primary magnetization curves, which were obtained under the assumptions of the theory of approach to ferromagnetic saturation described in by H. Kronm�ller. Test samples of the Fe78Si11B11 alloy were tape-shaped materials, which were subjected to isothermal annealing, not causing their crystallization. The investigated ribbons (tapes) were characterized by a very high saturation magnetization value of approximately 2T, which the thermal treatment has increased by about 10%. It was found that reason for the change of saturation magnetization of the investigated samples was the local rearrangement of atoms due to diffusion processes leading to the release of free volumes to the surface and combining of them into larger unstable defects called pseudodislocational dipoles.

scholarly journals A Novel Textile Stitch-Based Strain Sensor for Wearable End Users

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1469 ◽  
Author(s):  
Orathai Tangsirinaruenart ◽  
George Stylios
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistance ◽  
Body Movement ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Heart Monitoring ◽  
Textile Sensors ◽  
Good Repeatability ◽  
The Ideal

This research presents an investigation of novel textile-based strain sensors and evaluates their performance. The electrical resistance and mechanical properties of seven different textile sensors were measured. The sensors are made up of a conductive thread, composed of silver plated nylon 117/17 2-ply, 33 tex and 234/34 4-ply, 92 tex and formed in different stitch structures (304, 406, 506, 605), and sewn directly onto a knit fabric substrate (4.44 tex/2 ply, with 2.22, 4.44 and 7.78 tex spandex and 7.78 tex/2 ply, with 2.22 and 4.44 tex spandex). Analysis of the effects of elongation with respect to resistance indicated the ideal configuration for electrical properties, especially electrical sensitivity and repeatability. The optimum linear working range of the sensor with minimal hysteresis was found, and the sensor’s gauge factor indicated that the sensitivity of the sensor varied significantly with repeating cycles. The electrical resistance of the various stitch structures changed significantly, while the amount of drift remained negligible. Stitch 304 2-ply was found to be the most suitable for strain movement. This sensor has a wide working range, well past 50%, and linearity (R2 is 0.984), low hysteresis (6.25% ΔR), good gauge factor (1.61), and baseline resistance (125 Ω), as well as good repeatability (drift in R2 is −0.0073). The stitch-based sensor developed in this research is expected to find applications in garments as wearables for physiological wellbeing monitoring such as body movement, heart monitoring, and limb articulation measurement.

scholarly journals Characteristics of Lightweight Cellular Concrete and Effects on Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2678 ◽  
Author(s):  
Wei Yu ◽  
Xu Liang ◽  
Frank Mi-Way Ni ◽  
Abimbola Grace Oyeyi ◽  
Susan Tighe
Keyword(s):  
Mechanical Properties ◽  
Pore Structure ◽  
High Definition ◽  
Pore Characteristics ◽  
Software Applications ◽  
Solid Part ◽  
Electron Microscopes ◽  
Lab Test ◽  
Scanning Electron Microscopes ◽  
Cellular Concrete

This study investigated the pore structure and its effects on mechanical properties of lightweight cellular concrete (LCC) in order to understand more and detailed characteristics of such structure. As part of investigation, environment scanning electron microscopes (ESEM) and industrial high-definition (HD) macro photography camera were separately used to capture and compare images of specimens. Physical properties of the pore structure, including pore area, size, perimeter, fit ellipse, and shape descriptors, were studied based on the image processing technology and software applications. Specimens with three different densities (400, 475, and 600 kg/m3) were prepared in the laboratory. Firstly, the effects of density on the characteristics of pore structure were investigated; furthermore, mechanical properties (compressive strength, modulus of elasticity and Poisson’s ratio, flexural strength and splitting tensile strength of LCC) were tested. The relationships among pore characteristics, density, and mechanical properties were analyzed. Based on the results obtained from the lab test—comparisons made between specimens with high-densities and those with low-densities—it was found significant variability in bubble size, thickness, and irregularity of pores. Furthermore, the increase of density is accompanied by better mechanical properties, and the main influencing factors are the thickness of the solid part and the shape of the bubble. The thicker of solid part and more regular pores of LCC has, the better mechanical properties are.

Preparation of Polyurethane-Poly (Vinyl Alcohol) / Chitosan Blend Nanofiber Nonwovens by Coelectrospinning

2012 ◽  
Vol 602-604 ◽  
pp. 157-160
Author(s):  
Wei Min Kang ◽  
Jing Yan ◽  
Bo Wen Cheng
Keyword(s):  
Mechanical Properties ◽  
Vinyl Alcohol ◽  
Diameter Distribution ◽  
Poly Vinyl Alcohol ◽  
Technical Parameters ◽  
The Ideal

Polyurethane-poly (vinyl alcohol)/chitosan (PU-PVA/CS) blend nanofiber nonwovens were successfully prepared by coelectrospinning in this paper. The morphology, diameter and structure of the electrospun nanomaterials were examined by SEM and FITR, and their mechanical properties were tested. The diameter distribution of the nanofibers was measured by Image-Pro Plus. The results show that the ideal nanofibers with the diameter in 50-350 nm can be obtained with the proper technical parameters of PU and PVA/CS nanofibers as follows: the spinning voltage at 30 kV and 40 kV, the extruding speed at 6 mL/h and 0.5 ml/h, the collecting distance at 150 mm and 200 mm, respectively.

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