Processing and Mechanical Properties of Laminar Al2O3-Ni3Al Composites

1994 ◽  
Vol 350 ◽  
Author(s):  
J. H. Schneibel ◽  
K. B. Alexander
Keyword(s):  
Mechanical Properties ◽  
Thin Layer ◽  
Energy Absorption ◽  
Nickel Aluminide ◽  
Intermetallic Alloy ◽  
Interfacial Bonding ◽  
Three Point Bending

AbstractSeveral compositions of the intermetallic alloy Ni3Al were examined with respect to (a) their wetting of Al2O3 and (b) their energy absorption capability in Al2O3/Ni3Al laminates. Wetting is enhanced by small additions of carbon (e.g., 0.1 at. %), and bonding by additions of zirconium (e.g., 1 at. %). Chevron-notched laminate specimens were tested in three-point bending to assess the energy absorption due to the presence of a thin layer of Ni3Al. A nickel aluminide with the composition Ni-22Al-lZr-0.1C-0.1B was found to have a reasonable combination of wetting, adhesion and energy absorption. Interfacial bonding was found to be weak in all laminates.

Mechanical Properties of NiAl Nanocomposite Intermetallic Alloys With Varying Porosity

2009 ◽  
Author(s):  
Emily M. Hunt ◽  
Pilaka Murty
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Combustion Synthesis ◽  
Nickel Aluminide ◽  
Intermetallic Alloy ◽  
Atomic Scale ◽  
Focused Attention ◽  
Intermetallic Alloys ◽  
Nano Technology ◽  
Nano Scale

Recent advancements in the field of nano-technology focused attention on developing materials with new and useful characteristics. In particular, there is interest in designing nanocomposite thermites for combustion synthesis applications. The composite material consists of nano-scale particles that are in nearly atomic scale proximity but constrained from reaction until triggered. Once initiated, the reaction will become self-sustaining and a new intermetallic alloy product will be produced. An example of this type of reaction is between Ni and Al such that a nickel-aluminide alloy is produced (Eq. (1) [1].

The Graded Origami Structures

2015 ◽  
Author(s):  
Ruikang Xie ◽  
Jianmin Li ◽  
Yan Chen
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Engineering Application ◽  
Geometric Parameters ◽  
Sandwich Beams ◽  
Three Point Bending ◽  
Graded Structure ◽  
Sector Angle ◽  
Graded Structures ◽  
Bending Response

There are many excellent graded structures existing in nature to optimize the mechanical properties in various load situations by adjusting the distribution of materials. In this research, rigid origami and graded structure concept are combined together to form the graded origami structures. Seven methods are proposed, including changing the length of crease lines, changing the sector angle, changing the number of units, and the combinations of them. Two rigid origami patterns, Miura-ori and Arc-Miura, are chosen to generate the graded origami structures, and the geometric parameters of each pattern are studied. For engineering application, quasi-static three-point bending response of sandwich beams with graded Miura-ori core based on changing the number of units and changing both the length of crease lines and the sector angle is explored. The investigation reveals that sandwich beams with graded Miura-ori core have preferable energy absorption capability in this load situation compared with the normal Miura-ori core.

The Mechanical Properties of Organic Modified Epoxy Resin

2020 ◽  
Vol 43 (3) ◽  
pp. 10-14
Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Epoxy Resins ◽  
Mechanical Tests ◽  
Organic Modification ◽  
Three Point Bending ◽  
Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

scholarly journals Interfacial Strengthening of Graphene/Aluminum Composites through Point Defects: A First-Principles Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 738
Author(s):  
Xin Zhang ◽  
Shaoqing Wang
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Point Defects ◽  
Metal Matrix ◽  
Interfacial Bonding ◽  
Theoretical Research ◽  
Matrix Composites ◽  
Aluminum Composites ◽  
Single Vacancy ◽  
Design Guideline

The relationship between point defects and mechanical properties has not been fully understood yet from a theoretical perspective. This study systematically investigated how the Stone–Wales (SW) defect, the single vacancy (SV), and the double vacancy (DV) affect the mechanical properties of graphene/aluminum composites. The interfacial bonding energies containing the SW and DV defects were about twice that of the pristine graphene. Surprisingly, the interfacial bonding energy of the composites with single vacancy was almost four times that of without defect in graphene. These results indicate that point defects enhance the interfacial bonding strength significantly and thus improve the mechanical properties of graphene/aluminum composites, especially the SV defect. The differential charge density elucidates that the formation of strong Al–C covalent bonds at the defects is the most fundamental reason for improving the mechanical properties of graphene/aluminum composites. The theoretical research results show the defective graphene as the reinforcing phase is more promising to be used in the metal matrix composites, which will provide a novel design guideline for graphene reinforced metal matrix composites. Furthermore, the sp3-hybridized C dangling bonds increase the chemical activity of the SV graphene, making it possible for the SV graphene/aluminum composites to be used in the catalysis field.

scholarly journals Study on improvement of prefolded energy absorption device to constant resistance and its mechanical properties

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110368
Author(s):  
Dong An ◽  
Jiaqi Song ◽  
Hailiang Xu ◽  
Jingzong Zhang ◽  
Yimin Song ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Compression Test ◽  
Side Wall ◽  
Concave Side ◽  
Displacement Curve ◽  
Static Compression ◽  
Constant Resistance ◽  
The Impact ◽  
Force Displacement

When the rock burst occurs, energy absorption support is an important method to solve the impact failure. To achieve constant resistance performance of energy absorption device, as an important component of the support, the mechanical properties of one kind of prefolded tube is analyzed by quasi-static compression test. The deformation process of compression test is simulated by ABAQUS and plastic strain nephogram of the numerical model are studied. It is found that the main factors affecting the fluctuation of force-displacement curve is the stiffness of concave side wall. The original tube is improved to constant resistance by changing the side wall. The friction coefficient affects the folding order and form of the energy absorbing device. Lifting the concave side wall stiffness can improve the overall stiffness of energy absorption device and slow down the falling section of force-displacement curve. It is always squeezed by adjacent convex side wall in the process of folding, with large plastic deformation. Compared with the original one, the improved prefolded tube designed in this paper can keep the maximum bearing capacity ( Pmax), increase the total energy absorption ( E), improve the specific energy absorption (SEA), and decrease the variance ( S2) of force-displacement curve.

scholarly journals Static Mechanical Properties of Expanded Polypropylene Crushable Foam

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
Energy Absorption ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Strain Rates ◽  
Foam Density ◽  
Energy Absorption Capacity ◽  
Closed Cell

Closed-cell expanded polypropylene (EPP) foam is commonly used in car bumpers for the purpose of absorbing energy impacts. Characterization of the foam’s mechanical properties at varying strain rates is essential for selecting the proper material used as a protective structure in dynamic loading application. The aim of the study was to investigate the influence of loading strain rate, material density, and microstructure on compressive strength and energy absorption capacity for closed-cell polymeric foams. We performed quasi-static compressive strength tests with strain rates in the range of 0.2 to 25 mm/s, using a hydraulically controlled material testing system (MTS) for different foam densities in the range 20 g/dm3 to 220 g/dm3. The above tests were carried out as numerical simulation using ABAQUS software. The verification of the properties was carried out on the basis of experimental tests and simulations performed using the finite element method. The method of modelling the structure of the tested sample has an impact on the stress values. Experimental tests were performed for various loads and at various initial temperatures of the tested sample. We found that increasing both the strain rate of loading and foam density raised the compressive strength and energy absorption capacity. Increasing the ambient and tested sample temperature caused a decrease in compressive strength and energy absorption capacity. For the same foam density, differences in foam microstructures were causing differences in strength and energy absorption capacity when testing at the same loading strain rate. To sum up, tuning the microstructure of foams could be used to acquire desired global materials properties. Precise material description extends the possibility of using EPP foams in various applications.

scholarly journals Compressive Behaviour of Aluminium Pyramidal Lattice Material-Filled Tubes

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3817
Author(s):  
Yingjie Huang ◽  
Wenke Zha ◽  
Yingying Xue ◽  
Zimu Shi
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Al Alloy ◽  
Compressive Behaviour ◽  
Lattice Material ◽  
Empty Tube ◽  
Thin Walled

This study focuses on the uniaxial compressive behaviour of thin-walled Al alloy tubes filled with pyramidal lattice material. The mechanical properties of an empty tube, Al pyramidal lattice material, and pyramidal lattice material-filled tube were investigated. The results show that the pyramidal lattice material-filled tubes are stronger and provide greater energy absorption on account of the interaction between the pyramidal lattice material and the surrounding tube.

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