Mechanical properties, structure and performance of chemically vapor-deposited and physically vapor-deposited coated carbide tools

Abstract The sample preparation for transmission electron microscope can be done using a method known as "lift-out". This paper demonstrates a method of using a silver-gallium nanoneedle array for a quicker sharpening process of tungsten probes with better sample viewing, covering the fabrication steps and performance of needle-tipped probes for lift-out process. First, an array of high aspect ratio silver-gallium nanoneedles was fabricated and coated to improve their conductivity and strength. Then, the nanoneedles were welded to a regular tungsten probe in the focused ion beam system at the desired angle, and used as a sharp probe for lift-out. The paper demonstrates the superior mechanical properties of crystalline silver-gallium metallic nanoneedles. Finally, a weldless lift-out process is described whereby a nano-fork gripper was fabricated by attaching two nanoneedles to a tungsten probe.

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Preparation and performance evolution of enhancement polystyrene composites with graphene oxide/carbon nanotube hybrid aerogel: mechanical properties, electrical and thermal conductivity

Polymer Testing ◽

10.1016/j.polymertesting.2021.107283 ◽

2021 ◽

pp. 107283

Author(s):

Hui Xu ◽

Guojun Song ◽

Lina Zhang ◽

Zetian Zhao ◽

Zhitao Liu ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Graphene Oxide ◽

Carbon Nanotube ◽

And Performance ◽

Hybrid Aerogel

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Effects of Different Contents of Each Component on the Structural Stability and Mechanical Properties of Co-Cr-Fe-Ni High-Entropy Alloys

Applied Sciences ◽

10.3390/app11062832 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2832

Author(s):

Haibo Liu ◽

Cunlin Xin ◽

Lei Liu ◽

Chunqiang Zhuang

Keyword(s):

Mechanical Properties ◽

Structural Stability ◽

High Entropy Alloys ◽

Face Centered Cubic ◽

Obvious Effect ◽

High Entropy ◽

Precise Control ◽

Component Content ◽

Face Centered ◽

And Performance

The structural stability of high-entropy alloys (HEAs) is closely related to their mechanical properties. The precise control of the component content is a key step toward understanding their structural stability and further determining their mechanical properties. In this study, first-principle calculations were performed to investigate the effects of different contents of each component on the structural stability and mechanical properties of Co-Cr-Fe-Ni HEAs based on the supercell model. Co-Cr-Fe-Ni HEAs were constructed based on a single face-centered cubic (FCC) solid solution. Elemental components have a clear effect on their structure and performance; the Cr and Fe elements have an obvious effect on the structural stability and equilibrium lattice constant, respectively. The Ni elements have an obvious effect on stiffness. The Pugh ratios indicate that Cr and Ni addition may increase ductility, whereas Co and Fe addition may decrease it. With increasing Co and Fe contents or decreasing Cr and Ni contents, the structural stability and stiffness of Co-Cr-Fe-Ni HEAs are improved. The structural stability and mechanical properties may be related to the strength of the metallic bonding and covalent bonding inside Co-Cr-Fe-Ni HEAs, which, in turn, is determined by the change in element content. Our results provide the underlying insights needed to guide the optimization of Co-Cr-Fe-Ni HEAs with excellent mechanical properties.

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Effect of Structural Differences on the Mechanical Properties of 3D Integrated Woven Spacer Sandwich Composites

Materials ◽

10.3390/ma14154284 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4284

Author(s):

Lvtao Zhu ◽

Mahfuz Bin Rahman ◽

Zhenxing Wang

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Three Dimensional ◽

Sheet Thickness ◽

Physical And Mechanical Properties ◽

Sandwich Composites ◽

Computed Tomography Images ◽

And Performance ◽

Industrial Textiles ◽

Load Conditions

Three-dimensional integrated woven spacer sandwich composites have been widely used as industrial textiles for many applications due to their superior physical and mechanical properties. In this research, 3D integrated woven spacer sandwich composites of five different specifications were produced, and the mechanical properties and performance were investigated under different load conditions. XR-CT (X-ray computed tomography) images were employed to visualize the microstructural details and analyze the fracture morphologies of fractured specimens under different load conditions. In addition, the effects of warp and weft direction, face sheet thickness, and core pile height on the mechanical properties and performance of the composite materials were analyzed. This investigation can provide significant guidance to help determine the structure of composite materials and design new products according to the required mechanical properties.

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The potential use of lightweight cellular concrete in pavement application: a review

International Journal of Pavement Research and Technology ◽

10.1007/s42947-020-6003-8 ◽

2020 ◽

Vol 13 (6) ◽

pp. 686-696

Author(s):

Frank Mi-Way Ni ◽

Abimbola Grace Oyeyi ◽

Susan Tighe

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Ease Of Use ◽

Potential Candidate ◽

Actual Performance ◽

Freeze Thaw ◽

Lower Weight ◽

And Performance ◽

Potential Use ◽

Cellular Concrete

AbstractProtecting the pavement subgrade to increase the service life of road pavements is an aspect currently being explored. Several alternative pavement subbase materials are being considered, including Lightweight Cellular Concrete (LCC). Due to its lower weight, LCC incorporating industrial by-product, making it sustainable, and ease of use amongst other benefits, is seen as a potential candidate. This paper reports reviewing the potential application of LCC within the pavement structure with a specific application as a subbase. It examines the various properties such as modulus of elasticity, compressive and tensile strength, Water absorption, and freeze-thaw resistance necessary for pavement application. It also assesses its use in the field in Canada considering the design methods utilized. Some limitations and gaps for LCC application in pavements are also established and recommendations on how to further its use and performance. This review concludes that LCC possesses potential as a pavement subbase alternative; however, other mechanical properties like LCC’s fatigue life is essential. A comparative field study is also recommended to monitor actual performance and various factors on performance.

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Engineering the Surface and Mechanical Properties of Water Desalination Membranes Using Ultralong Carbon Nanotubes

Membranes ◽

10.3390/membranes8040106 ◽

2018 ◽

Vol 8 (4) ◽

pp. 106 ◽

Cited By ~ 5

Author(s):

Yehia M. Manawi ◽

Kui Wang ◽

Viktor Kochkodan ◽

Daniel J. Johnson ◽

Muataz A. Atieh ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Aspect Ratio ◽

Water Flux ◽

Contact Angles ◽

Water Desalination ◽

Membrane Properties ◽

Porous Membranes ◽

Water Contact ◽

And Performance

In this work, novel polysulphone (PS) porous membranes for water desalination, incorporated with commercial and produced carbon nanotubes (CNT), were fabricated and analyzed. It was demonstrated that changing the main characteristics of CNT (e.g., loading in the dope solutions, aspect ratio, and functionality) significantly affected the membrane properties and performance including porosity, water flux, and mechanical and surface properties. The water flux of the fabricated membranes increased considerably (up to 20 times) along with the increase in CNT loading. Conversely, yield stress and Young’s modulus of the membranes dropped with the increase in the CNT loading mainly due to porosity increase. It was shown that the elongation at fracture for PS/0.25 wt. % CNT membrane was much higher than for pristine PS membrane due to enhanced compatibility of commercial CNTs with PS matrix. More pronounced effect on membrane’s mechanical properties was observed due to compatibility of CNTs with PS matrix when compared to other factors (i.e., changes in the CNT aspect ratio). The water contact angle for PS membranes incorporated with commercial CNT sharply decreased from 73° to 53° (membrane hydrophilization) for membranes with 0.1 and 1.0 wt. % of CNTs, while for the same loading of produced CNTs the water contact angles for the membrane samples increased from 66° to 72°. The obtained results show that complex interplay of various factors such as: loading of CNT in the dope solutions, aspect ratio, and functionality of CNT. These features can be used to engineer membranes with desired properties and performance.

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