Fabrication and Fracture Test of Functionalized Graphene-PETI 5 Composite

2014 ◽  
Author(s):  
Adam McLaughlin ◽  
Byungki Kim
Keyword(s):  
Cyclic Loading ◽  
Fracture Strength ◽  
Room Temperature ◽  
Fuel Tank ◽  
Exfoliated Graphite ◽  
Functionalized Graphene ◽  
Fracture Test ◽  
Temperature Changes ◽  
The Matrix ◽  
The Ideal

The development of a composite cryogenic fuel tank is desirable for the creation of a reusable single-stage launch vehicle. The cyclic loading and temperature changes experienced during launch and re-entry conditions result in the microcracking of conventional composites. To increase the fracture strength of this composite, a property often limited by the matrix, the nanoplatelet known as graphene or exfoliated graphite, has been introduced. Three nanocomposites were produced using graphene and Phenylethynyl Terminated Imide oligomer (PETI-5). The nanocomposites were machined in to flexure samples and tested at room temperature. Results from these tests indicate that the ideal concentration of graphene in our PETI-5 nanocomposite is 0.08%.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

ALCHEMI of B2-Ordered Fe50Al45Me5 alloys

1996 ◽  
Vol 54 ◽  
pp. 548-549
Author(s):  
Ian M. Anderson
Keyword(s):  
Room Temperature ◽  
Iron Aluminide ◽  
Low Density ◽  
Intermetallic Alloys ◽  
Practical Applications ◽  
Alloying Additions ◽  
Site Distribution ◽  
Good Corrosion Resistance ◽  
Room Temperature Ductility ◽  
The Matrix

B2-ordered iron aluminide intermetallic alloys exhibit a combination of attractive properties such as low density and good corrosion resistance. However, the practical applications of these alloys are limited by their poor fracture toughness and low room temperature ductility. One current strategy for overcoming these undesirable properties is to attempt to modify the basic chemistry of the materials with alloying additions. These changes in the chemistry of the material cannot be fully understood without a knowledge of the site-distribution of the alloying elements. In this paper, the site-distributions of a series of 3d-transition metal alloying additions in B2-ordered iron aluminides are studied with ALCHEMI.A series of seven alloys of stoichiometry Fe50AL45Me5, with Me = {Ti, V, Cr, Mn, Co, Ni, Cu}, were prepared with identical heating cycles. Microalloying additions of 0.2% B and 0.1% Zr were also incorporated to strengthen the grain boundaries, but these alloying additions have little influence on the matrix chemistry and are incidental to this study.

The butterfly martensite nucleation in an iron and nickel alloy

1990 ◽  
Vol 48 (4) ◽  
pp. 906-907
Author(s):  
Q.Z. Chen ◽  
X.F. Wu ◽  
T. Ko
Keyword(s):  
Nickel Alloy ◽  
Ethyl Alcohol ◽  
Dislocation Structure ◽  
Martensite Transformation ◽  
Room Temperature ◽  
The Matrix

Some butterfly martensite nuclei were observed in an Fe-27.6Ni-0.89V-0.05C alloy. The alloy was austenitized at 1200°C for 1 hour. Some samples were aged at 850° C for 40 minutes and quenched in 10% brine at room temperature. All the samples were cooled in ethyl alcohol for martensite transformation.A nucleus in an unaged specimen is shown in Fig.1. The nucleus has certain contrast different from the matrix and is shaped like one wing of a butter fly martensite. The SADP of the circled region is measured to be: da=dh, and approximate to dγ(111) and dm(110) with ∠AOB = 55° . It is similar to [011]f.c.c and b patterns in the anglez ∠AOB and the ratio ra/rb, respectively. The SADP shows that the structure of the nucleus is between f.c.c and b.c.c. The dislocation structure within the nucleus is shown in Fig.2. Their Burgers vectors and line directions are also given in it. There are many long dislocations near it without dislocations piled up as shown in Fig.3.Long dislocations are closed at one end as an envelope.

Lead inclusions in aluminium

1989 ◽  
Vol 157 ◽  
Author(s):  
E. Johnson ◽  
L. Gråbaek ◽  
J. Bohr ◽  
A. Johansen ◽  
L. Sarholt-Kristensen ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Room Temperature ◽  
Noble Gas ◽  
Melting Transition ◽  
X Ray Diffraction ◽  
Free Surfaces ◽  
The Matrix ◽  
Mean Size ◽  
The Mean ◽  
Spontaneous Phase

ABSTRACTIon implantation at room temperature of lead into aluminium leads to spontaneous phase separation and formation of lead precipitates growing topotactically with the matrix. Unlike the highly pressurised (∼ 1–5 GPa) solid inclusions formed after noble gas implantations, the pressure in the lead precipitates is found to be less than 0.12 GPa.Recently we have observed the intriguing result that the lead inclusions in aluminium exhibit both superheating and supercooling [1]. In this paper we review and elaborate on these results. Small implantation-induced lead precipitates embedded in an aluminium matrix were studied by X-ray diffraction. The (111) Bragg peak originating from the lead crystals was followed during several temperature cycles, from room temperature to 678 K. The melting temperature for bulk lead is 601 K. In the first heating cycle we found a superheating of the lead precipitates of 67 K before melting occurred. During subsequent cooling a supercooling of 21 K below the solidification point of bulk lead was observed. In the subsequent heating cycles this hysteresis at the melting transition was reproducible. The full width of the hysteresis loop slowly decreased to 62 K, while the mean size of the inclusions gradually increased from 14.5 nm to 27 nm. The phenomena of superheating and supercooling are thus most pronounced for the small crystallites. The persistence of the hysteresis loop over successive heating cycles demonstrate that its cause is intrinsic in nature, and it is believed that the superheating originates from the lack of free surfaces of the lead inclusions.

L-cysteine functionalized graphene quantum dots for sub-ppb detection of As (III)

2021 ◽  
Author(s):  
Md. Farhan Naseh ◽  
Neelam Singh ◽  
Jamilur R. Ansari ◽  
Ashavani Kumar ◽  
Tapan Sarkar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Room Temperature ◽  
Graphene Quantum Dots ◽  
Optical Characterization ◽  
Functionalized Graphene ◽  
Transmission Electron ◽  
Sensitivity And Selectivity ◽  
Structural Characterizations

Abstract Here, we report functionalized graphene quantum dots (GQDs) for the optical detection of arsenic at room temperature. GQDs with the fluorescence of three fundamental colors (red, green, and blue) were synthesized and functionally capped with L-cysteine (L-cys) to impart selectively towards As (III) by exploiting the affinity of L-cys towards arsenite. The optical characterization of GQDs was carried out using UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectrometry and the structural characterizations were performed using transmission electron microscopy. The fluorescence results showed instantaneous quenching in intensity when the GQDs came in contact with As (III) for all test concentrations over a range from 0.025 ppb to 25 ppb, which covers the permissible limit of arsenic in drinking water. The experimental results suggested excellent sensitivity and selectivity towards As (III).

Multi-functional biomimetic graphene induced transformation of Fe3O4 to ε-Fe2O3 at room temperature

RSC Advances ◽  
2015 ◽  
Vol 5 (109) ◽  
pp. 89488-89497 ◽  
Author(s):  
Soumya Bhattacharya ◽  
Anirban Roychowdhury ◽  
Dipankar Das ◽  
Suprabha Nayar
Keyword(s):  
Room Temperature ◽  
Functionalized Graphene ◽  
Protein Polymer ◽  
Graphene Nanoflakes ◽  
Visual Evidence

A schematic showing the formation of nanosized ε-Fe2O3 in protein–polymer functionalized graphene; the templated IONPs literally coat the graphene nanoflakes. G–IONP colloidal fluid, TEM and MFM micrographs provide visual evidence of the same.

scholarly journals Mechanical properties and microstructural investigation of polypropylene/exfoliated graphite nanoplatelets/ nano-magnesium oxide composites

2018 ◽  
Vol 7 (2) ◽  
pp. 897
Author(s):  
A I. Alateyah ◽  
F H. Latief
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Exfoliated Graphite ◽  
Graphite Nanoplatelets ◽  
Microstructural Investigation ◽  
The Matrix ◽  
Exfoliated Graphite Nanoplatelets ◽  
Polypropylene Matrix ◽  
Xrd Patterns ◽  
Oxide Composites

Polypropylene/exfoliated graphite nanoplatelets composites reinforced with a low concentration of nano-magnesia have been successfully fabricated, using injection molding machine. The mechanical properties and microstructure of the composites were investigated, in the present study. The XRD patterns of the composites showed the peaks of xGnP and n-MgO, where the intensity of the xGnP peaks became stronger with increasing the concentration of xGnP added into polypropylene matrix. In addition, the SEM micrographs revealed a good dispersion of fillers within the matrix. The results showed that increasing the amount of exfoliated graphite nanoplatelets up to 10 wt. % resulted in increasing the composite flexural strength, flexural modulus, and hardness up to 35% and 91%, 6.7%, respectively, compared to the monolithic polypropylene.  

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