Synthesis of As-Cast WCu Composite Containing Micro- and Nano-Size Tungsten Particles Using Aluminothermic Reduction

JOM ◽  
2022 ◽  
Author(s):  
Chu Cheng ◽  
Ke-Xing Song ◽  
Zi-Wei Song ◽  
Ling-Feng Wang ◽  
Qian-Qian Xu ◽  
...  
Keyword(s):  
Aluminothermic Reduction ◽  
Nano Size

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

Aluminum particles with nano-size defects in their alumina shells and their thermal oxidation properties

2021 ◽  
pp. 159877
Author(s):  
Weiqiang Tang ◽  
Rongjie Yang ◽  
Jinghui Hu ◽  
Jianmin Li ◽  
Fei Xiao ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Aluminum Particles ◽  
Oxidation Properties ◽  
Nano Size

scholarly journals A New Approach to Obtaining Nano-Sized Graphene Oxide for Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1327
Author(s):  
Paulina Bolibok ◽  
Bartosz Szymczak ◽  
Katarzyna Roszek ◽  
Artur P. Terzyk ◽  
Marek Wiśniewski
Keyword(s):  
Graphene Oxide ◽  
Biomedical Applications ◽  
Effective Concentration ◽  
New Approach ◽  
Spectral Changes ◽  
Dimethyl Sulfoxide Solution ◽  
Aggregation Processes ◽  
Initial Oxygen ◽  
Half Maximal Effective Concentration ◽  
Nano Size

Graphene oxide (GO) is one of the most exciting and widely used materials. A new method of nanographene oxide (n-GO) formation is presented. The described unique sequence of ultrasonication in dimethyl sulfoxide solution allows us to obtain different sizes of n-GO sheets by controlling the timing of the cutting and re-aggregation processes. The obtained n-GO exhibits only minor spectral changes, mainly due to the formation of S-containing surface groups; thus, it can be concluded that the material is not reduced during the process. Maintaining the initial oxygen functionalities together with the required nano-size (down to 200 nm) and high homogeneity are beneficial for extensive applications of n-GO. Moreover, we prove that the obtained material is evidently biocompatible. The calculated half-maximal effective concentration (EC50) increases by 5-fold, i.e., from 50 to 250 µg/mL, when GO is converted to n-GO. As a consequence, the new n-GO neither disturbs blood flow even in the narrowest capillaries nor triggers a toxic influence in surrounding cells. Thus, it can be a serious candidate for drugs and biomolecule carriers administered systemically.

scholarly journals Facile Synthesis of High-Quality Nano-Size 10B-Enriched Fibers of Hexagonal Boron Nitride

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 222
Author(s):  
Pervaiz Ahmad ◽  
Mayeen Uddin Khandaker ◽  
Fida Rehman ◽  
Nawshad Muhammad ◽  
Mohammad Rashed Iqbal Faruque ◽  
...  
Keyword(s):  
Boron Nitride ◽  
High Intensity ◽  
Hexagonal Boron Nitride ◽  
Internal Space ◽  
Facile Synthesis ◽  
High Quality ◽  
Crystalline Nature ◽  
Nano Size ◽  
Advanced Applications

The interesting properties of hexagonal boron nitride (h-BN) and its potential uses in thermo-structural advanced applications have been limited or restricted by its inherent brittleness, which can easily be eliminated by its fibers (h-BN) in nanoscale dimensions. The current study is based on the synthesis of nanoscale 10B-enriched fibers of h-BN (10BNNFs) from 10B in the precursors instead of B in two-hour annealing at 900 °C and one-hour growth at 1000 °C. All of the 10BNNFs are randomly curved and highly condensed or filled from 10h-BN species with no internal space or crack. XRD peaks reported the 10h-BN phase and highly crystalline nature of the synthesized 10BNNFs. 10h-BN phase and crystalline nature of 10BNNFs are confirmed from high-intensity peaks at 1392 (cm−1) in Raman and FTIR spectroscopes.

scholarly journals Hydrothermal synthesis of nanocrystalline hydroxyapatite–graphene nanosheet on Ti-6Al-7Nb: mechanical and in vitro corrosion performance

2021 ◽  
Vol 32 (4) ◽  
Author(s):  
Oktay Yigit ◽  
Burak Dikici ◽  
Niyazi Ozdemir
Keyword(s):  
Hydrothermal Reaction ◽  
Hybrid Coatings ◽  
Stoichiometric Ratio ◽  
Corrosion Performance ◽  
Graphene Nanosheet ◽  
Graphene Layers ◽  
Nanocrystalline Hydroxyapatite ◽  
One Step ◽  
Nano Size

AbstractThe hybrid coatings containing the graphene nano-sheet (GNS) and nano-hydroxyapatite (nHA) phases have been successfully synthesized on Ti6Al7Nb alloys by a one-step hydrothermal method. The hydrothermal reaction was carried out for 24 h at 200 °C. The GNS ratio has been altered as 1, 3, 5 and 7 wt.% in the coatings and, the results have compared with non- GNS containing coatings. The effect of the GNS ratio on the microstructure, hardness, and in vitro corrosion responses has been investigated in detail. The characterizations of the coatings were carried out by SEM, EDS, AFM, XRD and, FTIR. The corrosion behavior of the hybrid coatings was compared in Kokubo’s solution at 37 °C by using potentiodynamic polarization tests. The results showed that the hydroxyapatite phases were deposed on the graphene layers with nano-size nucleation with its Ca/P stoichiometric ratio. The best hydrophilicity (~52°) property has been obtained in nHA/3GNS coatings. In addition, the corrosion rates of coatings increased in the following order: nHA/3GNS < nHA/1GNS < nHA/7GNS < nHA/5GNS < only nHA.

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