Deformation Behavior and Mechanical Properties of Suspended Double‐Layer Graphene Ribbons Induced by Large AFM Indentation Forces

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

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Severe plastic deformation of Al-1%Cu Alloy processed by a Simple Cyclic Extrusion Compression technique

International Journal of Computational Physics Series ◽

10.29167/a1i1p77-90 ◽

2018 ◽

Vol 1 (1) ◽

pp. 77-90

Author(s):

Walaa Abdelaziem ◽

Atef Hamada ◽

Mohsen A. Hassan

Keyword(s):

Mechanical Properties ◽

Plastic Deformation ◽

Severe Plastic Deformation ◽

Deformation Behavior ◽

Cast Alloy ◽

Surface Hardness ◽

Grain Structure ◽

Compression Technique ◽

Cu Alloy ◽

Cyclic Extrusion Compression

Severe plastic deformation is an effective method for improving the mechanical properties of metallic alloys through promoting the grain structure. In the present work, simple cyclic extrusion compression technique (SCEC) has been developed for producing a fine structure of cast Al-1 wt. % Cu alloy and consequently enhancing the mechanical properties of the studied alloy. It was found that the grain structure was significantly reduced from 1500 µm to 100 µm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of the as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. Also, cyclic extrusion deformation increased the surface hardness of the alloy by 49 % after two passes. FE-simulation model was adopted to simulate the deformation behavior of the material during the cyclic extrusion process using DEFORMTM-3D Ver11.0. The FE-results revealed that SCEC technique was able to impose severe plastic strains with the number of passes. The model was able to predict the damage, punch load, back pressure, and deformation behavior.

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Double-layer graphene on photonic crystal waveguide electro-absorption modulator with 12 GHz bandwidth

Nanophotonics ◽

10.1515/nanoph-2019-0381 ◽

2019 ◽

Vol 9 (8) ◽

pp. 2377-2385 ◽

Cited By ~ 4

Author(s):

Zhao Cheng ◽

Xiaolong Zhu ◽

Michael Galili ◽

Lars Hagedorn Frandsen ◽

Hao Hu ◽

...

Keyword(s):

Photonic Crystal ◽

Double Layer ◽

Slow Light ◽

Modulation Depth ◽

Photonic Crystal Waveguide ◽

Optical Modulators ◽

Layer Graphene ◽

Silicon Photonic ◽

On Chip ◽

Silicon Based

AbstractGraphene has been widely used in silicon-based optical modulators for its ultra-broadband light absorption and ultrafast optoelectronic response. By incorporating graphene and slow-light silicon photonic crystal waveguide (PhCW), here we propose and experimentally demonstrate a unique double-layer graphene electro-absorption modulator in telecommunication applications. The modulator exhibits a modulation depth of 0.5 dB/μm with a bandwidth of 13.6 GHz, while graphene coverage length is only 1.2 μm in simulations. We also fabricated the graphene modulator on silicon platform, and the device achieved a modulation bandwidth at 12 GHz. The proposed graphene-PhCW modulator may have potentials in the applications of on-chip interconnections.

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