Investigations on the mechanics and tribology of multilayer graphene nanosheet in TiAl aviation composites

Requirements of low energy consumption and material-volume reduction in the aerospace industry have spurred improvements of mechanical and tribological behaviors of TiAl (TA) alloys. TA-graphene (TAG) has poorer mechanical properties (6.02 ± 0.42 GPa nano-hardness, 150 ± 12.32 GPa elasticity modulus, and 802 ± 21 MPa yield strength) than (6.25 ± 0.52 GPa nano-hardness, 159 ± 14.21 GPa elasticity modulus, and 850 ± 19 MPa yield strength) of TA-graphene-silver (TAGS). Multilayer graphene nanosheets were curled into small loops to resist the applied forces, and helped to improve the mechanical properties of the TAGS. Subsequently, the graphene nanosheets enhanced the tribological performances as observed by the ball-on-disk tribometer. The following factors were primarily responsible for more excellent tribological behaviors (approximately 0.27 friction coefficient, 2.82 × 10−4 mm3 N−1 m−1 wear rate) of TAGS than those of the TAG: intra-lamellar separation of graphene, graphene-enhanced capacity of wear scar, plastic deformation of silver, the excellent cooperation lubrication of graphene-silver, the low-hardness lubrication film on the grain-refined layer, the well-distributed film grain, and low grain orientation angles.

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In situ tensile fracturing of multilayer graphene nanosheets for their in-plane mechanical properties

Nanotechnology ◽

10.1088/1361-6528/ab3cd3 ◽

2019 ◽

Vol 30 (47) ◽

pp. 475708 ◽

Cited By ~ 1

Author(s):

Peifeng Li ◽

Ke Cao ◽

Chenchen Jiang ◽

Shang Xu ◽

Libo Gao ◽

...

Keyword(s):

Mechanical Properties ◽

Graphene Nanosheets ◽

Multilayer Graphene ◽

Tensile Fracturing

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A setup to characterize the tensile mechanical properties of poly(L-lactic acid) materials applied in bioresorbable polymer stents

Journal of Instrumentation ◽

10.1088/1748-0221/16/12/p12005 ◽

2021 ◽

Vol 16 (12) ◽

pp. P12005

Author(s):

G. Zhao ◽

R. He ◽

X. Li ◽

J. Zhang ◽

J. Cheng ◽

...

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Yield Strength ◽

Biodegradable Polymer ◽

Elasticity Modulus ◽

Breaking Elongation ◽

Measurement Results ◽

Different Shapes ◽

Bioresorbable Polymer ◽

Set Up

Abstract A method for testing mechanical properties of miniature poly(L-lactic acid)(PLLA) specimens is instrumented and set up in this research. This method is specially designed to measure mechanical properties, including elasticity modulus, yield strength and breaking elongation, of miniature PLLA specimens in three different shapes at various tensile speeds and temperatures. Moreover, the measurement results are significantly dependent on the tensile speeds and temperatures. This phenomenon further verifies the obvious existence of the viscoelasticity of PLLA. Finally, it can be concluded that, with this method, mechanical properties of PLLA can be better investigated and understood, especially for PLLA used for biodegradable polymer stents.

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The effect of plastic deformation on mechanical properties of aluminium matrix composites reinforced with 2D crystals

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-1110803 ◽

2020 ◽

Vol 111 (8) ◽

pp. 632-638

Author(s):

Jaroslaw Wozniak ◽

Mateusz Petrus ◽

Marek Kostecki ◽

Tomasz Cygan ◽

Andrzej Olszyna

Keyword(s):

Mechanical Properties ◽

Plastic Deformation ◽

Yield Strength ◽

Physical And Mechanical Properties ◽

Compressive Yield Strength ◽

Multilayer Graphene ◽

Matrix Composites ◽

Plasma Sintering ◽

Spark Plasma ◽

2D Crystals

Abstract In this study, AA6061 matrix composites reinforced with multilayer graphene and MoS2 were analyzed. The composites were prepared by powder metallurgy using the spark plasma sintering and spark plasma texturing methods. Microstructure, physical and mechanical properties were investigated and compared with unreinforced AA6061 sinter and AA6061 sheet plate. The results showed that the application of spark plasma texturing positively influences the relative density and compressive yield strength of AA6061 matrix composites. Moreover, in composites with MoS2, significant differences in compressive yield strength between the centre and the edge of the sintered compacts were noticed. These differences are related to the formation of the MoAl12 phase as a result of the temperature gradient generated in the graphite die during sintering by the spark plasma texturing.

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Melt- vs. Non-Melt Blending of Complexly Processable Ultra-High Molecular Weight Polyethylene/Cellulose Nanofiber Bionanocomposite

Polymers ◽

10.3390/polym13030404 ◽

2021 ◽

Vol 13 (3) ◽

pp. 404

Author(s):

Nur Sharmila Sharip ◽

Hidayah Ariffin ◽

Tengku Arisyah Tengku Yasim-Anuar ◽

Yoshito Andou ◽

Yuki Shirosaki ◽

...

Keyword(s):

Mechanical Properties ◽

Molecular Weight ◽

Tensile Strength ◽

Yield Strength ◽

Young’S Modulus ◽

High Molecular Weight ◽

Melt Processing ◽

Cellulose Nanofiber ◽

Melt Blending ◽

Ultra High Molecular Weight

The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.

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Enhanced lattice distortion, yield strength, critical resolved shear stress, and improving mechanical properties of transition-metals doped CrCoNi medium entropy alloy

RSC Advances ◽

10.1039/d1ra02073k ◽

2021 ◽

Vol 11 (38) ◽

pp. 23719-23724

Author(s):

Md. Lokman Ali

Keyword(s):

Mechanical Properties ◽

Shear Stress ◽

Transition Metals ◽

Yield Strength ◽

Lattice Distortion ◽

Critical Resolved Shear Stress

The effect of transition-metals (TM) addition on the mechanical properties of CrCoNi medium entropy alloys (MEAs) was investigated.

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Synthesis and fabrication of Ni-SiO2 nanosphere-decorated multilayer graphene nanosheets composite electrode for highly sensitive amperometric determination of guaifenesin drug

Microchemical Journal ◽

10.1016/j.microc.2021.106325 ◽

2021 ◽

pp. 106325

Author(s):

Song-Jeng Huang ◽

Sathiyalingam Kannaiyan ◽

Krishnan Venkatesh ◽

Srikanth Cheemalapati ◽

Ahmed S. Haidyrah ◽

...

Keyword(s):

Composite Electrode ◽

Graphene Nanosheets ◽

Multilayer Graphene ◽

Amperometric Determination ◽

Highly Sensitive

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Enhanced electrical conductivity and mechanical properties in thermally stable fine-grained copper wire

Communications Materials ◽

10.1038/s43246-021-00150-1 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Qingzhong Mao ◽

Yusheng Zhang ◽

Yazhou Guo ◽

Yonghao Zhao

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Electrical Conductivity ◽

Yield Strength ◽

High Speed ◽

Copper Wire ◽

Rapid Development ◽

Dislocation Slip ◽

Ultrafine Grains ◽

The Wire

AbstractThe rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.

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Mechanical Properties of Hybrid Graphene Nanoplatelet-Nanosilica Filled Unidirectional Basalt Fibre Composites

Nanomaterials ◽

10.3390/nano11061468 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1468

Author(s):

Ummu Raihanah Hashim ◽

Aidah Jumahat ◽

Mohammad Jawaid

Keyword(s):

Mechanical Properties ◽

Polymer Composites ◽

Glass Fibre ◽

Graphene Nanosheets ◽

High Surface ◽

High Surface Area ◽

High Strength ◽

Basalt Fibre ◽

Graphene Nanoplatelet ◽

Dispersion State

Basalt fibre (BF) is one of the most promising reinforcing natural materials for polymer composites that could replace the usage of glass fibre due to its comparable properties. The aim of adding nanofiller in polymer composites is to enhance the mechanical properties of the composites. In theory, the incorporation of high strength and stiffness nanofiller, namely graphene nanoplatelet (GNP), could create superior composite properties. However, the main challenges of incorporating this nanofiller are its poor dispersion state and aggregation in epoxy due to its high surface area and strong Van der Waals forces in between graphene sheets. In this study, we used one of the effective methods of functionalization to improve graphene’s dispersion and also introducing nanosilica filler to enhance platelets shear mechanism. The high dispersive silica nanospheres were introduced in the tactoids morphology of stacked graphene nanosheets in order to produce high shear forces during milling and exfoliate the GNP. The hybrid nanofiller modified epoxy polymers were impregnated into BF to evaluate the mechanical properties of the basalt fibre reinforced polymeric (BFRP) system under tensile, compression, flexural, and drop-weight impact tests. In response to the synergistic effect of zero-dimensional nanosilica and two-dimensional graphene nanoplatelets enhanced the mechanical properties of BFRP, especially in Basalt fibre + 0.2 wt% GNP/15 wt% NS (BF-H0.2) with the highest increment in modulus and strength to compare with unmodified BF. These findings also revealed that the incorporation of hybrid nanofiller contributed to the improvement in the mechanical properties of the composite. BF has huge potential as an alternative to the synthetic glass fibre for the fabrication of mechanical components and structures.

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Effects of ionic liquid types on the tribological, mechanical, and thermal properties of ionic liquid modified graphene/polyimide shape memory composites

High Performance Polymers ◽

10.1177/0954008321996769 ◽

2021 ◽

pp. 095400832199676

Author(s):

Yuting Ouyang ◽

Qiu Zhang ◽

Xiukun Liu ◽

Ruan Hong ◽

Xu Xu ◽

...

Keyword(s):

Mechanical Properties ◽

Ionic Liquid ◽

Composite Materials ◽

Shape Memory ◽

Recovery Rate ◽

Shape Recovery ◽

Graphene Nanosheets ◽

Mechanical And Thermal Properties ◽

Thermal And Mechanical Properties ◽

Modified Graphene

Different ionic liquid modified graphene nanosheets (IG) were induced into polyimide (PI) to improve the tribological, thermal, and mechanical properties of shape memory IG/PI composites. The results demonstrated that when using 1-aminoethyl-3-methylimidazole bromide to modify graphene nanosheets (IG-1), the laser-driven shape recovery rate of IG-1/PI composites (IGPI-1) reached 73.02%, which was 49.36% higher than that of pure PI. In addition, the IGPI-1 composite materials reached the maximum shape recovery rate within 15 s. Additionally, under dry sliding, the addition of IG can significantly improve the tribological properties of composite materials. IGPI-1 exhibited the best self-lubricating properties. Compared with pure PI, the friction coefficient (0.19) and wear rate (2.62 × 10–5) mm3/Nm) were reduced by 44.1% and 24.2%, respectively, and the T10% of IGPI-1 increased by 32.2°C. The Tg of IGPI-1 reached 256.5°C, which was 8.4°C higher than that of pure PI. In addition, the tensile strength and modulus of IGPI-1 reached 82.3 MPa and 1.18 GPa, which were significantly increased by 33.6% and 29.8%, respectively, compared with pure PI. We hope that this work will be helpful for the preparation of shape memory materials with excellent tribological, thermal, and mechanical properties.

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