Fabrication of Al2O3/BN Nanocomposites by Chemical Processing and Their Mechanical Properties

2005 ◽  
Vol 20 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Takafumi Kusunose ◽  
Yoon-Ho Kim ◽  
Tohru Sekino ◽  
Takuya Matsumoto ◽  
Norihito Tanaka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Young’S Modulus ◽  
Hot Pressing ◽  
Young's Modulus ◽  
High Strength ◽  
Synthesis Process ◽  
Chemical Processing ◽  
Chemical Route ◽  
Nanocomposite Structures

Al2O3/BN nanocomposites were fabricated through a novel chemical route involving hot-pressing of α–Al2O3 powders covered partly with turbostratic BN (t-BN). The nano-sized hexagonal BN (h-BN) particles were found to be homogeneously dispersed within the Al2O3 grains as well as at grain boundaries, which is indicative of nanocomposite structures. Thus, the present nanocomposites exhibited the unique properties of high strength and low Young’s modulus associated with nanocomposites. This paper discusses in detail the synthesis process and microstructural features of these materials.

Development of Biomedical Near β Titanium Alloys

2009 ◽  
Vol 618-619 ◽  
pp. 303-306 ◽  
Author(s):  
Zhen Tao Yu ◽  
Gui Wang ◽  
Xi Qun Ma ◽  
Matthew S. Dargusch ◽  
Jian Ye Han ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Solution Treatment ◽  
High Strength ◽  
Alloy Chemistry ◽  
Solution Treated ◽  
Strength And Plasticity ◽  
Hot Rolled

The effects of alloy chemistry and heat treatment on the microstructure and mechanical properties of Ti-Nb-Zr-Mo-Sn near  type titanium alloys have been investigated. Near β titanium alloys consisting of non-toxic alloying elements Mo, Nb, Zr, Sn possess a low Young’s modulus, and moderate strength and plasticity. As the hot rolled TLM alloy (Ti-25Nb-3Zr-3Mo-2Sn) possesses high strength and low Young’s modulus a detailed investigation is performed for this alloy. Solution treatment of the hot rolled TLM alloy reduces strength and increases ductility without affecting the Young’s modulus. Ageing of the solution treated TLM alloy reduces elongation and increases the Young’s modulus with little change in strength. Both solution treated and aged conditions show features of two stage yielding associated with a strain induced martensitic transformation.

Mechanical Properties of Hydrogen Functionalized Graphyne - A Molecular Dynamics Investigation

2012 ◽  
Vol 472-475 ◽  
pp. 1813-1817 ◽  
Author(s):  
Yu Lin Yang ◽  
Zhe Yong Fan ◽  
Ning Wei ◽  
Yong Ping Zheng
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
High Strength ◽  
Strength And Stiffness ◽  
Dynamics Simulations ◽  
Structure Engineering

In this paper the mechanical properties of a series of hydrogen functionalized graphyne are investigated through acting tensile loads on the monolayer networks. Molecular dynamics simulations are performed to calculate the fracture strains and corresponding maximum forces for pristine graphyne along both armchair and zigzag directions. Furthermore, hydrogen functionalized graphynes with different functionalization sites are analyzed to investigate the effect of functionlization on the mechanical performance. Finally, Young's modulus of all the investigated architectures are computed. The obtained results show that monolayer graphyne is mechanically stable with high strength and stiffness, and the mechanical performance can be tuned through structure engineering and functionalization.

Microstructure Formation Mechanism of (Al2O3+TiB2+Al3Ti)/Al Composites Fabricated by Reactive Hot Pressing

2007 ◽  
Vol 353-358 ◽  
pp. 1439-1442 ◽  
Author(s):  
Gui Song Wang ◽  
Lin Geng
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Formation Mechanism ◽  
Hot Pressing ◽  
Young's Modulus ◽  
Microstructure Formation ◽  
Sem And Tem ◽  
Reactive Hot Pressing ◽  
Tib2 Particles

The two (Al2O3+TiB2+Al3Ti)/Al composites were fabricated from Al-B2O3-TiO2 and Al-B-TiO2 raw powders by reactive hot pressing, respectively. The microstructure of in situ two composites was analyzed by OM, SEM and TEM. The results showed that coarse Al3Ti blocks with several tens of micrometers size were formed during hot pressing. The equiaxed Al2O3 particulates and hexagonal TiB2 particulates with finer sizes were formed in the composites simultaneously. The microstructure formation mechanism of (Al2O3+TiB2+Al3Ti)/Al composites were discussed. The results showed that Al2O3 reinforcements were formed on the surface of TiO2 or B2O3 powder and TiB2 particles were formed on B or B2O3 powders. The formation of coarse Al3Ti block is result from continuous diffusion of Ti in liquid Al during reactive hot pressing. In addition, there are fine Al3Ti precipitates exist in the composite fabricated from Al-B-TiO2 powders. This contributes to the improved mechanical properties in terms of yield and ultimate stresses and Young’s modulus of the composite.

Influence of Hot Pressing Parameters on Mechanical Properties of PP-HA Bio-Composites

2009 ◽  
Author(s):  
Mousa Younesi ◽  
Mohammad Ebrahim Bahrololoom ◽  
Hamidreza Fooladfar
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Hot Pressing ◽  
Young's Modulus ◽  
Impact Resistance ◽  
Hot Press ◽  
Different Types ◽  
Press Molding

This paper focuses on the effects of pressure and temperature in hot press molding on the mechanical properties of polypropylene-hydroxyapatite composites with two different types of silanated and unsilanated hydroxyapatite. Density, crystallinity, ultimate tensile strength, Young’s modulus and impact resistance were evaluated for the two types of composites. Increasing pressure caused enhancement of density, crystallinity, MFI, ultimate tensile strength and Young’s modulus. Increases in temperature increased MFI, ultimate tensile strength and Young’s modulus whilst decreased impact resistance of composites. Effects of increasing pressure and temperature on the mechanical properties of polypropylene-silanated hydroxyapatite were less than their effects on the mechanical properties of polypropylene-unsilanated hydroxyapatite. Micrographs showed changes in fracture mode from ductile to brittle with increasing pressure and temperature during hot press molding.

Micro Texture-Induced Variation of Mechanical Properties of Electroplated Copper Thin Films

2007 ◽  
Author(s):  
Muneyuki Otani ◽  
Kazuhiko Sakutani ◽  
Kinji Tamakawa ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Grain Boundaries ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Bulk Material ◽  
Tensile Load ◽  
Columnar Structure ◽  
Grain Boundary Sliding ◽  
Electroplated Copper

The mechanical properties of copper thin films formed by cold-rolling and electroplating were measured using a tensile test and nano-indentation. Both the Young’s modulus and the tensile strength of the films were found to vary drastically depending on the microstructure of the films. The Young’s modulus of the cold-rolled film was almost same as that of the bulk material. However, the Young’s modulus of the electroplated thin film was about a fourth of that of the bulk material. The microstructure of the electroplated film was polycrystalline and a columnar structure with a diameter of a few hundred-micron. The strength of the grain boundaries of the columnar grains seemed to be rather week. Such a columnar structure with porous grain boundaries caused the cooperative grain boundary sliding. As a result, the effective elasticity of the film became rather low and the superplastic deformation of the film appearred under an uni-axial tensile load. In addition, there was a sharp distribution of Young’s modulus along the thickness direction of the film. Though the modulus near the surface of the film was close to that of the bulk material, it decreased drastically to about a half at the depth of 1 μm. There was also a planar distribution of Young’s modulus near the surface of the film.

Low Rigidity Ti-Nb-Ta-X (X=Cr, Zr, Ag, In) Alloys with Improved Properties

2016 ◽  
Vol 695 ◽  
pp. 157-163
Author(s):  
Mihai Branzei
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Cyclic Loading ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
High Strength ◽  
Cast State ◽  
Biological Media ◽  
Good Workability

The paper is focused on microstructure characterisation of five bulk metastable β-type Ti-based alloys, with improved mechanical properties, composed of non-toxic (bio inert) elements like: Nb, Ta, Cr, Zr, Ag, and In. These types of alloys designed in this study, are expected to have also higher corrosion resistance in biological media and good performance such as lower Young’s modulus of elasticity, greater strength, good workability, also in as cast state. However, high strength as well as low Young’s modulus is required for the implants subjected to cyclic loading under complicated stress conditions. Thus, the major aim is decreasing the Young’s modulus and increasing the tenacity of these alloys.

Reinforcing Open Cell Aluminum Foams by Amorphous Ni-P Coating

2016 ◽  
Vol 879 ◽  
pp. 684-689
Author(s):  
Zhen Dong Li ◽  
Ying Jie Huang ◽  
Xin Fu Wang ◽  
Xing Fu Wang ◽  
Fu Sheng Han
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Surface Coating ◽  
Young's Modulus ◽  
High Strength ◽  
Functional Material ◽  
Aluminum Foams ◽  
Open Cell ◽  
Coated Film ◽  
Enhancement Technologies

Open cell aluminum foams are a promising multi-functional material that has potential application in a variety of engineering fields, but their too low mechanical properties may restrict their applications in some load bearing conditions. To overcome this shortcoming, enhancement methods have been widely investigated in recent years including surface enhancement technologies. In the present study, an electrodeposition process was utilized to coat an amorphous Ni-P coating on the cell strut surface of open cell aluminum foams. The results show that the coated film exhibits typical amorphous feature and is thermally stable. The average nanohardness and Young’s modulus are 7.0GPa and 118.1GPa, respectively, in which the Young’s modulus is even 1.6 times higher than that of aluminum (70GPa). It is because the high strength film that leads to significantly enhancement of the foams. The compression strength of the foam was increased from about 0.2MPa to 11.9MPa when the film thickness was around 65μm. These results demonstrate that the surface coating does be an effective way to improve the mechanical properties of open cell aluminum foams.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

scholarly journals First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Salloom ◽  
S. A. Mantri ◽  
R. Banerjee ◽  
S. G. Srinivasan
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
First Principles ◽  
Young's Modulus ◽  
Group Vi ◽  
Group V ◽  
Β Phase ◽  
Ti Alloys ◽  
Ω Phase ◽  
Stabilizer Concentration

AbstractFor decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.

scholarly journals Tailoring a Low Young Modulus for a Beta Titanium Alloy by Combining Severe Plastic Deformation with Solution Treatment

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3467
Author(s):  
Anna Nocivin ◽  
Doina Raducanu ◽  
Bogdan Vasile ◽  
Corneliu Trisca-Rusu ◽  
Elisabeta Mirela Cojocaru ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Solution Treatment ◽  
Young Modulus ◽  
Orthopedic Implants ◽  
Beta Titanium Alloy

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti–Nb–Zr–Fe–O alloy of β-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of etot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young’s modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young’s modulus of about 48–49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of β-stabilizing alloying elements, especially the Zr/Nb ratio.

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