scholarly journals Extraordinary tensile strength and ductility of scalable nanoporous graphene

2019 ◽  
Vol 5 (2) ◽  
pp. eaat6951 ◽  
Author(s):  
Hamzeh Kashani ◽  
Yoshikazu Ito ◽  
Jiuhui Han ◽  
Pan Liu ◽  
Mingwei Chen
Keyword(s):  
Tensile Strength ◽  
Large Scale ◽  
Carbon Materials ◽  
Three Dimensional ◽  
High Strength ◽  
Graphene Sheets ◽  
Nanoporous Graphene ◽  
Flaw Sensitivity ◽  
Relationship Of ◽  
Strength And Ductility

While the compressive strength-density scaling relationship of ultralight cellular graphene materials has been extensively investigated, high tensile strength and ductility have not been realized in the theoretically strongest carbon materials because of high flaw sensitivity under tension and weak van der Waals interplanar bonding between graphene sheets. In this study, we report that large-scale ultralight nanoporous graphene with three-dimensional bicontinuous nanoarchitecture shows orders of magnitude higher strength and elastic modulus than all reported ultralight carbon materials under both compression and tension. The high-strength nanoporous graphene also exhibits excellent tensile ductility and work hardening, which are comparable to well-designed metamaterials but until now had not been realized in ultralight cellular materials. The excellent mechanical properties of the nanoporous graphene benefit from seamless graphene sheets in the bicontinuous nanoporosity that effectively preserves the intrinsic strength of atomically thick graphene in the three-dimensional cellular nanoarchitecture.

Deformation Measurements on Full-Scale Fracture Tests of Pre-Cracked Tubular Joints

2003 ◽  
Author(s):  
Bijan Talei-Faz ◽  
Feargal P. Brennan ◽  
Stuart Robson
Keyword(s):  
Large Scale ◽  
Fatigue Testing ◽  
Three Dimensional ◽  
Steel Structures ◽  
High Strength ◽  
Static Strength ◽  
Full Scale ◽  
Structural Testing ◽  
Tubular Joints ◽  
Large Steel

A series of six static strength destructive tests were performed on full-scale pre-cracked tubular welded T-joints manufactured from a high strength weldable steel used in the construction of offshore Jack-Up platforms. All specimens had at least one through-thickness fatigue crack at the weld toe, from a previous fatigue-testing programme. The tests were aimed at analysing the residual static strength of the cracked members. As destructive tests are costly to perform, every effort was made to maximise the data collected. This included the use of a novel photogrammetric technique to provide three-dimensional measurement in real time of the deformation in the vicinity of the brace-chord intersection. The technique has been used for large-scale structural testing in a number of civil and aerospace applications, but to the author’s knowledge this is the first time that it has been employed for the full-scale mechanical testing of large steel structures. This paper describes the details of the photogrammetric technique applied to the large steel specimens which were loaded to failure, resulting in the total separation of the intersecting members. It is hoped that the technique can be used to generate information which can be used in conjunction with finite element or other numerical analyses to increase the accuracy and reliability of modelling cracked tubular joints.

Large scale production of nanoporous graphene sheets and their application in lithium ion battery

Carbon ◽  
2015 ◽  
Vol 84 ◽  
pp. 469-478 ◽  
Author(s):  
Jianan Zhang ◽  
Binghao Guo ◽  
Yongqiang Yang ◽  
Wenzhuo Shen ◽  
Yanmei Wang ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Large Scale ◽  
Lithium Ion ◽  
Graphene Sheets ◽  
Scale Production ◽  
Large Scale Production ◽  
Nanoporous Graphene

High Strength Titanium Rods Produced by Thermomechanical Powder Consolidation

2016 ◽  
Vol 861 ◽  
pp. 147-152
Author(s):  
Fei Yang ◽  
Brian Gabbitas ◽  
Ajit Singh ◽  
Chung Fu Wang
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Pure Titanium ◽  
Hot Extrusion ◽  
High Strength ◽  
Sintered Titanium ◽  
Vacuum Sintering ◽  
Powder Consolidation ◽  
Strength And Ductility

In this paper, pure titanium rods, with high strength and ductility, were prepared by vacuum sintering titanium powder compacts at 1300oC for 2h and then hot extruding the as-sintered titanium billets at 900oC in air. The microstructure and property changes, after vacuum sintering and hot extrusion, were investigated. The results showed clear evidence of porosity in the microstructure of as-sintered titanium billet and tensile testing of as-sintered material gave yield strength, ultimate tensile strength and ductility values of 570MPa, 602MPa and 4%, respectively. After extrusion at 900oC, no obvious pores could be seen in the microstructure of as-extruded titanium rod, and the mechanical properties were significantly improved. The yield strength, ultimate tensile strength and the ductility reached 650MPa, 705MPa and 20%, respectively, which are much higher than values for CP titanium (grade 4), with a yield strength of 480MPa, ultimate tensile strength of 550MPa and ductility of 15%. The fracture characteristics of as-sintered and as-extruded titanium rods have also been investigated.

scholarly journals Modulation of Multiple Precipitates for High Strength and Ductility in Al-Cu-Mn Alloy

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7383
Author(s):  
Linxiang Liu ◽  
Zhijun Wang ◽  
Qingfeng Wu ◽  
Zhongsheng Yang ◽  
Kexuan Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
High Strength ◽  
Mechanical Behaviors ◽  
High Tensile Strength ◽  
Transmission Electron ◽  
Evolution Pattern ◽  
Elongation To Failure ◽  
High Elongation ◽  
Strength And Ductility

The category and morphology of precipitates are essential factors in determining the mechanical behaviors of aluminum alloys. It is a great challenge to synthetically modulate multiple precipitates to simultaneously improve strength and ductility. In the present work, by optimizing the precipitations of the GP zone, θ’-approximant and θ’ phase for an Al-Cu-Mn alloy, a high tensile strength of 585 MPa with large elongation of 12.35% was achieved through pre-deformation and aging. The microstructure evolution pattern was revealed by detailed characterizations of scanning electron microscopy and transmission electron microscopy. It was found that such high tensile strength of the samples was due to a combination of strengthening by the high density of dispersive fine precipitates and dislocations, and the high elongation to failure was primarily attributed to the multimodal precipitates and elimination of precipitation-free zones along the grain boundaries. The strategy proposed here is a promising way of preparing ultra-strong Al-Cu-Mn alloys.

Optically Transparent Nanocomposite Based on Cellulose Nanofibers from Newspapers and Polyurethane

2012 ◽  
Vol 174-177 ◽  
pp. 905-911 ◽  
Author(s):  
Xue Ting Li ◽  
Da Gang Li ◽  
Li Xu ◽  
Yu Mei Wang ◽  
Dong Liang Lin
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Cellulose Nanofibers ◽  
Three Dimensional ◽  
High Strength ◽  
Wood Powder ◽  
Sem Images ◽  
High Transparency ◽  
Dimensional Network ◽  
Optically Transparent

The goal of this paper was to develop an optically transparent nanocomposite with high strength by reinforcing polyurethane (PU) with cellulose nanofibers (CNFs) extracted from newspapers. The FE-SEM images show that through chemical and mechanical treatments, newspaper CNFs with diameters ranged from 20 to 100 nm and an aspect ratio of over 1000 were successfully obtained as well as wood powder. They were cross-linked together and formed a special three-dimensional network structure. The nanocomposite was fabricated by impregnating the CNF sheet into transparent PU resin and cured under ultraviolet. Results demonstrate that the transparency of newspaper CNF/PU nanocomposite was as high as wood CNF/PU nanocomposite. The elastic modulus and tensile strength of newspaper CNF/PU composite were increased roughly eighteen times and two times respectively while retaining the high transparency of PU, which was nearly the same with wood CNF/PU composite.

COPPER ALLOY No. 862

Alloy Digest ◽  
1979 ◽  
Vol 28 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Copper Alloy ◽  
Iron Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Copper Zinc ◽  
Strengthening Element ◽  
Strength And Ductility

Abstract Copper Alloy No. 862 is a copper-zinc-aluminum-manganese-iron alloy; aluminum is the principal strengthening element. It is classified as a high-strength yellow brass; its typical tensile strength is 95,000 psi. It has an excellent combination of strength and ductility along with good resistance to corrosion. Its numerous applications include cams, valve stems and marine hardware. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Cu-365. Producer or source: Copper alloy foundries.

scholarly journals Strategies to Achieve High Strength and Ductility of Pulsed Electrodeposited Nanocrystalline Co-Cu by Tuning the Deposition Parameters

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5194
Author(s):  
Killang Pratama ◽  
Christian Motz
Keyword(s):  
Tensile Strength ◽  
Current Density ◽  
Duty Cycle ◽  
Pulse Current ◽  
High Strength ◽  
Internal Stresses ◽  
Low Duty Cycle ◽  
Deposition Parameters ◽  
Pulse On Time ◽  
Strength And Ductility

Strategies to improve tensile strength and ductility of pulsed electrodeposited nanocrystalline Co-Cu were investigated. Parameters of deposition, which are pulse current density, duty cycle, and pulse-on time were adjusted to produce nanocrystalline Co-Cu deposits with different microstructures and morphologies. The most significant improvement of strength and ductility was observed at nanocrystalline Co-Cu deposited, at a low duty cycle (10%) and a low pulse-on time (0.3 ms), with a high pulse current density (1000 A/m2). Enhancement of ductility of nanocrystalline Co-Cu was also obtained through annealing at 200 °C, while annealing at 300 °C leads to strengthening of materials with reduction of ductility. In the as deposited state, tensile strength and ductility of nanocrystalline Co-Cu is strongly influenced by several factors such as concentration of Cu, grain size, and processing flaws (e.g., crystal growth border, porosity, and internal stresses), which can be controlled by adjusting the parameters of deposition. In addition, the presence of various microstructural features (e.g., spinodal and phase decomposition), as well as recovery processes induced by annealing treatments, also have a significant contribution to the tensile strength and ductility.

High Strength and Ductility in Multi-Directional Forged Wrought Aluminum Alloys

2014 ◽  
Vol 1064 ◽  
pp. 26-31 ◽  
Author(s):  
Li Fei Pan ◽  
Lin Chen ◽  
Wei Lin Yan
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Artificial Aging ◽  
Natural Aging ◽  
High Strength ◽  
Dislocation Slip ◽  
High Ductility ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum ◽  
Strength And Ductility

A wrought aluminum alloy 3004 was processed by multi-directional forging (MF), natural aging and artificial aging. The samples possess high strength and high ductility after processing. Grain size in samples was reduced evidently. The strength of samples was enhanced by dispersing ultrafine precipitate particles within the grains, reducing grain-size after MF and aging. The ductility was improved due to reducing the forging stress during aging. Moreover, a dispersing ultrafine precipitate particles widespread within the grains after aging, which helps to accumulate dislocations, increase the dislocation storage capability and resist dislocation slip that lead up to increasing work hardening, the ductility was also enhanced. The tensile strength and ductility of the alloy are 422.4 MPa and 11.95%, respectively.

Compromising high strength and ductility in nanoglass–metallic glass nanolaminates

RSC Advances ◽  
2016 ◽  
Vol 6 (16) ◽  
pp. 13548-13553 ◽  
Author(s):  
Sara Adibi ◽  
Paulo S. Branicio ◽  
Roberto Ballarini
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Metallic Glass ◽  
Molecular Dynamics Simulations ◽  
Large Scale ◽  
High Strength ◽  
Dynamics Simulations ◽  
Thick Layers ◽  
Strength And Ductility

Large-scale molecular-dynamics simulations are used to investigate the mechanical properties of 50 nm diameter Cu64Zr36 nanolaminate nanopillars constructed from 5 nm thick layers of metallic glass (MG) or MG and 5 nm grain sized nanoglass.

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