Growth of AlN by Reactive Gas Injection of Nitrogen in an AlMg Matrix

The primary objective of the present research was to provide a fundamental understanding of the processing science necessary to fabricate the Aluminum Nitride (AIN) reinforced Aluminum-Magnesium (AIMg) composites via Reactive Gas (N2) Injection in the AIMg alloy melt. Aluminum nitride (AlN) matrix composites were prepared by a novel approach. It was possible to produce a considerable amount of AIN particles in the AI alloy matrix at a reaction temperature as low as 900 °C utilizing the in-situ nitration reaction process developed in the present study. The volume fraction of AIN increases almost linearly with increasing the magnesium (Mg) content in the alloy and the reaction time. The shapes of AIN particles were found to have different forms, whose sizes were in the range from submicron to a few microns. From the present study, it is concluded that the new innovative in-situ nitridation process developed in the present study can be successfully applied for processing of high strength AIMg/AIN composites. For particles and composite structure characterization some methods were used, including: scanning microscopy, quantitative analysis of selected composite regions and XRD analyses. Composite structure and reinforcement distribution was compared with use of quantitative analysis. Morphology and diffraction pattern of aluminum nitride particles was shown. Typical structure of studied composites with microanalysis results was indicated. Aluminum nitride dispersion change was represented.

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Effect of Volume Fraction of Reinforcement on the Microstructure and Mechanical Properties of In Situ (TiB+TiC)/Ti Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.137 ◽

2011 ◽

Vol 335-336 ◽

pp. 137-141 ◽

Cited By ~ 1

Author(s):

Yuong Chen ◽

Chang Jiang Zhang ◽

Fan Tao Kong ◽

Hong Zhi Niu ◽

Fang Wu ◽

...

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Tensile Strength ◽

Elastic Modulus ◽

Room Temperature ◽

Volume Fraction ◽

Microstructural Analysis ◽

Matrix Composites ◽

Alloy Matrix

In the present study, Ti-6Al-2.5Sn-4Zr-0.7Mo-0.3Si-0.3Y alloy matrix composites reinforced with TiB and TiC were fabricated by combustion-assisted cast utilizing the reaction between titanium and B4C, graphite. The microstructure, room temperature mechanical properties were presented and discussed. Microstructural analysis of the composites revealed that the prior β grain size as well as the thickness of α colony significantly refined with increasing of volume fraction. At room temperature (RT), tensile strength and elastic modulus increase significantly, while the ductility drops gradually possibly because of the cracking of TiB whiskers and TiC particles.

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Chemical partitioning of elements in Ni-base MC-carbide reinforced eutetic superalloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007504x ◽

1983 ◽

Vol 41 ◽

pp. 250-251

Author(s):

E. F. Koch ◽

E. L. Hall ◽

S. W. Yang

Keyword(s):

Alloy Composition ◽

Volume Fraction ◽

Lattice Mismatch ◽

Turbine Blades ◽

Eutectic Alloys ◽

Alloy Matrix ◽

X Ray ◽

Gas Turbine Blades ◽

Analytical Electron ◽

Analytical Electron Microscope

The plane-front solidified eutectic alloys consisting of aligned tantalum monocarbide fibers in a nickel alloy matrix are currently under consideration for future aircraft and gas turbine blades. The MC fibers provide exceptional strength at high temperatures. In these alloys, the Ni matrix is strengthened by the precipitation of the coherent γ' phase (ordered L12 structure, nominally Ni3Al). The mechanical strength of these materials can be sensitively affected by overall alloy composition, and these strength variations can be due to several factors, including changes in solid solution strength of the γ matrix, changes in they γ' size or morphology, changes in the γ-γ' lattice mismatch or interfacial energy, or changes in the MC morphology, volume fraction, thermal stability, and stoichiometry. In order to differentiate between these various mechanisms, it is necessary to determine the partitioning of elemental additions between the γ,γ', and MC phases. This paper describes the results of such a study using energy dispersive X-ray spectroscopy in the analytical electron microscope.

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In-situ domain structure characterization of Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals under alternating current electric field poling

Acta Materialia ◽

10.1016/j.actamat.2021.116853 ◽

2021 ◽

pp. 116853

Author(s):

Chaorui Qiu ◽

Zhuo Xu ◽

Zheyi An ◽

Jinfeng Liu ◽

Guanjie Zhang ◽

...

Keyword(s):

Electric Field ◽

Domain Structure ◽

Alternating Current ◽

Structure Characterization ◽

Electric Field Poling ◽

Current Electric Field

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Macroscopical monolayer films of ordered arrays of gold nanoparticles as SERS substrates for in-situ quantitative detection in aqueous solutions

Nanoscale ◽

10.1039/d1nr03864h ◽

2021 ◽

Author(s):

Lixiang Xing ◽

Cui Wang ◽

Yi Cao ◽

Jihui Zhang ◽

Haibing Xia

Keyword(s):

Gold Nanoparticles ◽

Volume Fraction ◽

Water Volume ◽

Quantitative Detection ◽

Monolayer Films ◽

Au Nps ◽

Sers Substrates ◽

Ordered Arrays ◽

Water Volume Fraction

In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of...

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Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process

Materials ◽

10.3390/ma14071767 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1767

Author(s):

Yuhong Jiao ◽

Jianfeng Zhu ◽

Xuelin Li ◽

Chunjie Shi ◽

Bo Lu ◽

...

Keyword(s):

Mechanical Properties ◽

Matrix Composite ◽

Compression Strength ◽

Casting Process ◽

Al Alloy ◽

Pyrolysis Process ◽

Alloy Matrix ◽

Al Matrix Composite ◽

Al Matrix

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.

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Rabbit aortic medial thickness under relaxed and specified simulated in vivo conditions

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1983.245.4.h623 ◽

1983 ◽

Vol 245 (4) ◽

pp. H623-H627

Author(s):

G. Schneiderman ◽

W. F. Pritchard ◽

C. A. Ramirez ◽

C. K. Colton ◽

K. A. Smith ◽

...

Keyword(s):

Quantitative Analysis ◽

Mean Arterial Pressure ◽

Aortic Wall ◽

Macromolecular Transport ◽

Liquid Silicone ◽

Normal Mean ◽

Longitudinal Extension ◽

Media Layer

A method is presented for measuring the thickness of the intima-media layer of the normal rabbit descending thoracic aortic wall under both relaxed (excised) and specified simulated in vivo conditions. The in vivo conditions were simulated by maintaining the aorta in situ at its normal longitudinal extension while perfusing its lumen at the normal mean arterial pressure with a mixture of liquid silicone polymer and a catalyst, thus providing physiological radial distension. After the rubber cured, both relaxed and extended-distended tissue segments were obtained from adjacent sites on the same aorta. These tissue segments were fixed and further processed for measurement of their medial thicknesses by light microscopy. This data was used to estimate the ratio of the medial thickness of the relaxed, excised aorta to that under in vivo conditions, 1.72 +/- 0.15. This information is required for quantitative analysis of data obtained from previous studies of in vivo macromolecular transport across the rabbit thoracic aortic wall.

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Tungsten particles reinforced high-entropy alloy matrix composite prepared by in-situ reaction

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2020.158037 ◽

2020 ◽

pp. 158037

Author(s):

Gang Chen ◽

Tao Luo ◽

Shucheng Shen ◽

Jixiang Zheng ◽

Xiaotian Tang ◽

...

Keyword(s):

Matrix Composite ◽

High Entropy Alloy ◽

Alloy Matrix ◽

High Entropy ◽

In Situ Reaction

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Thermodynamics of In Situ Formation of Mg2Si and MgO in AZ91D /Flyash Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.378 ◽

2011 ◽

Vol 686 ◽

pp. 378-381

Author(s):

Si Rong Yu ◽

Zhi Qiu Huang ◽

Jia An Liu

Keyword(s):

Fly Ash ◽

Thermodynamic Calculation ◽

Interfacial Reactions ◽

Mg Alloy ◽

Free Enthalpy ◽

Alloy Matrix ◽

Microstructure Observation ◽

Enthalpy Changes ◽

Fly Ash Cenospheres

Novel AZ91D Mg alloy/fly-ash cenospheres (AZ91D/FAC) composites were fabricated by melt stir technique. The thermodynamic analyses of the interfacial reactions, the microstructure observation, and the phase analyses of the AZ91D/FAC composites were investigated. The results showed that the cenospheres were almost filled with Mg alloy matrix. In-situ MgO and Mg2Si phases were formed in Mg alloy matrix and near the interfaces between the cenospheres and Mg alloy matrix. Through the thermodynamic calculation, it can be found that the standard free enthalpy changes of these interfacial reactions are all negative at the temperature of Mg alloy melt preparation in this work, and these reactions can occur.

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