Effect of Uniaxial Compressive Stress during Formation of Porous Aluminum by Mechanochemical Reaction on its Mechanical Properties

2014 ◽  
Vol 922 ◽  
pp. 632-637
Author(s):  
K. Sawamoto ◽  
Noboru Nakayama
Keyword(s):  
Mechanical Properties ◽  
Compressive Stress ◽  
Pure Water ◽  
Mechanochemical Reaction ◽  
Compression Tests ◽  
Porous Aluminum ◽  
Wide Range ◽  
Powder Particles ◽  
Al Powder ◽  
The Individual

Porous Al is a lightweight material with excellent heat insulation and sound absorption properties and is expected to be used in a wide range of applications. A method based on mechanochemical reactions has been developed as an environmentally friendly approach to porous Al production. Pure Al powder reacts with pure water to form a coating layer of Al (OH)3 on the surface of the powder particles. Adjacent particles then bind together by adhesion of their coating layers. Since a large number of voids remain between the individual particles, the compact is classified as porous Al. In the present study, a mixture of pure Al powder and pure water was subjected to uniaxial compressive stresses ranging from 0 to 100 MPa to form porous Al. The mechanical properties of the resulting compact were evaluated in terms of the amount of H2 produced, the density, the Al (OH)3 texture, the amount of Al (OH)3 formed, and the results of subsequent compression tests. The density of the porous Al was found to increase with increasing compressive stress during formation. The largest amounts of H2 (800 ml) were produced under a compressive stress of 10 MPa. As the compressive stress was increased, the total amount of generated Al (OH)3 increased, was approximately constant from 30 to 50 MPa, and then decreased. The initial maximum stress, the plateau stress, and the absorbed energy increased with increasing compressive stress and were 100 MPa, 17.5 MPa, and 10.1 MJ/m3, respectively, for a compressive stress of 100 MPa.

scholarly journals In-Depth Comparison of an Industrially Extruded Powder and Ingot Al Alloys

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1483
Author(s):  
David Bombač ◽  
Peter Cvahte ◽  
Martin Balog ◽  
Goran Kugler ◽  
Milan Terčelj
Keyword(s):  
Mechanical Properties ◽  
Hot Extrusion ◽  
Hot Compression ◽  
Hot Forming ◽  
Compression Tests ◽  
Extrusion Press ◽  
Conventional Aluminum Alloy ◽  
Al Powder ◽  
Thermal Stability Of ◽  
Suitable Process

An industrial press was used to consolidate compacted aluminum powder with a nominal diameter in the range of 1 µm. Direct and indirect hot-extrusion processes were used, and suitable process parameters were determined from heating conditions, ram speeds and billet temperatures. For comparison, a direct-extrusion press for hot extrusion of a conventional aluminum alloy AA 1050 was used. The extruded Al powder showed better mechanical properties and showed a thermal stability of the mechanical properties after annealing treatments. To increase the theoretical density of the directly extruded Al powder, single-hit hot-compression tests were carried out. Activation energies for hot forming were calculated from hot-compression tests carried out in the temperature range 300–580 °C, at different strain rates. Processing maps were used to demonstrate safe hot-working conditions, to obtain an optimal microstructure after hot forming of extruded Al powder.

Microstructure and Mechanical Properties of Rapidly Solidified Al-Fe-Ni-Mg Alloys

2011 ◽  
Vol 674 ◽  
pp. 165-170 ◽  
Author(s):  
Anna Kula ◽  
Ludwik Blaz ◽  
Makoto Sugamata
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Rapid Solidification ◽  
Spray Deposition ◽  
Research Work ◽  
Mg Alloys ◽  
Solid Solution Hardening ◽  
Compression Tests ◽  
Microstructure And Mechanical Properties ◽  
Wide Range

Rapid solidification (RS) combined with following mechanical consolidation of RS powders is considered as a valuable commercial method for the production of a wide range of metallic materials having fine-grained structures. Reported research results for various alloys demonstrate better compositional homogeneity, smaller grain size and relatively fine precipitates distributed homogenously in RS alloys than that for the materials produced by conventional metallurgical processing. The effect of rapid solidification on the microstructure and mechanical properties of selected Al-Fe-Ni-Mg alloys have been investigated. The basic item of the research work was obtaining aluminum PM materials strengthened by highly-dispersed transition metal compounds and aluminum-magnesium solid solution. Rapid solidification (RS) of Al-4Fe-4Ni and Al-4Fe-4Ni-5Mg alloys was performed by means of gas atomizing of the molten alloy and the spray deposition on the rotating water-cooled copper roll. Using typical powder metallurgy (PM) methods, i.e. cold pressing, vacuum degassing and hot extrusion, the RS-flakes were consolidated to the bulk PMmaterials. For comparison purposes, the conventionally cast and hot extruded Al-4Fe-4Ni and Al-4Fe-4Ni-5Mg alloys were studied as well. Mechanical properties of as-extruded materials were examined by compression tests performed at 293 K – 873 K. It was found that relatively high strength of as-extruded PM materials was accompanied by high ductility of samples deformed by hot compression test. Structural observations confirmed beneficial influence of rapid solidification on effective refining of intermetallic compounds, although some inhomogeneity of fine precipitates distribution was observed. Nevertheless, it was considered that an effective increase of the microhardness and strength of tested RS materials mostly result from achieved dispersion of structural components and can be intensified by solid solution hardening due to Mg-addition.

The Effects of Operational, Testing and Material Characterisations On the Change in Yield Strength From Plate to Pipe

2021 ◽  
Author(s):  
Jingsi Jiao ◽  
Cheng Lu ◽  
Valerie Linton ◽  
Frank Barbaro
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Yield Strength ◽  
Finite Element Model ◽  
Mechanical Performance ◽  
Element Model ◽  
Critical Knowledge ◽  
Operational Testing ◽  
Wide Range ◽  
The Individual

Abstract The mechanical performance of the pipe sample has a direct influence on their application in real environments and a significant economic impact on manufacturers, especially when the pipe products do not meet required specifications. There is often a change in the yield strength from plate to pipe due to strain hardening and the Bauschinger effect. The current work sets out to provide a critical knowledge base for this change, with emphasizing the important influence of the plate mechanical properties on the pipe. So that the quality of pipe can be further ensured. In the work, firstly, the historical data of the pipe yield strength were collected and plotted together from a wide range of published sources to provide a broad quantitative insight, which provides a quantitative review on the parameters that govern the final pipe yield strength. Secondly, a Finite Element model of the pipe forming and mechanical evaluation was developed and then validated with available industrial testing results, in where the effects of operational and testing parameters on the pipe yield strength were analysed and discussed in detail. Finally, using the validated Finite Element model, a parametric study was conducted to dissect the individual role that each of the material parameters plays on changing the yield strength from plate to pipe. We found that the yield strength of the pipe can differ significantly. This work sheds lights on the desired plate mechanical properties to optimize the final pipe yield strength.

Experimental study on the mechanical properties of biological hydrogels of different concentrations

2020 ◽  
Vol 28 (6) ◽  
pp. 685-695
Author(s):  
Khurshid Alam ◽  
Anwarul Hasan ◽  
Muhammad Iqbal ◽  
Jamal Umer ◽  
Sujan Piya
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Precise Measurement ◽  
Three Dimensional ◽  
Crosslinking Density ◽  
Compression Tests ◽  
Cell Functions ◽  
Wide Range ◽  
Tension And Compression ◽  
Cellular Mechanobiology

BACKGROUND: Biological hydrogels provide a conducive three-dimensional extracellular matrix environment for encapsulating and cultivating living cells. Microenvironmental modulus of hydrogels dictates several characteristics of cell functions such as proliferation, adhesion, self-renewal, differentiation, migration, cell morphology and fate. Precise measurement of the mechanical properties of gels is necessary for investigating cellular mechanobiology in a variety of applications in tissue engineering. Elastic properties of gels are strongly influenced by the amount of crosslinking density. OBJECTIVE: The main purpose of the present study was to determine the elastic modulus of two types of well-known biological hydrogels: Agarose and Gelatin Methacryloyl. METHODS: Mechanical properties such as Young’s modulus, fracture stress and failure strain of the prescribed gels with a wide range of concentrations were determined using tension and compression tests. RESULTS: The elastic modulus, failure stress and strain were found to be strongly influenced when the amount of concentration in the hydrogels was changed. The elastic modulus for a lower level of concentration, not considered in this study, was also predicted using statistical analysis. CONCLUSIONS: Closed matching of the mechanical properties of the gels revealed that the bulk tension and compression tests could be confidently used for assessing mechanical properties of delicate biological hydrogels.

The Influence of Processing Parameters on the Mechanical Properties of Selectively Laser Melted Stainless Steel Microlattice Structures

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
S. Tsopanos ◽  
R. A. W. Mines ◽  
S. McKown ◽  
Y. Shen ◽  
W. J. Cantwell ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Cross Sections ◽  
Processing Parameters ◽  
Full Density ◽  
Laser Exposure ◽  
Compression Tests ◽  
Stainless Steel 316L ◽  
The Individual ◽  
Block Structures

The rapid manufacturing process of selective laser melting has been used to produce a series of stainless steel 316L microlattice structures. Laser power and laser exposure time are the two processing parameters used for manufacturing the lattice structures and, therefore, control the quality and mechanical properties of microlattice parts. An evaluation of the lattice material was undertaken by manufacturing a range of struts, representative of the individual trusses of the microlattices, as well as, microlattice block structures. Low laser powers were shown to result in significantly lower strand strengths due to the presence of inclusions of unmelted powder in the strut cross-sections. Higher laser powers resulted in struts that were near to full density as the measured strengths were comparable to the bulk 316L values. Uniaxial compression tests on microlattice blocks highlighted the effect of manufacturing parameters on the mechanical properties of these structures and a linear relationship was found between the plateau stress and elastic modulus relative to the measured relative density.

scholarly journals 3D Printing of Thermoplastic Elastomers: Role of the Chemical Composition and Printing Parameters in the Production of Parts with Controlled Energy Absorption and Damping Capacity

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3551
Author(s):  
Marina León-Calero ◽  
Sara Catherine Reyburn Valés ◽  
Ángel Marcos-Fernández ◽  
Juan Rodríguez-Hernandez
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
3D Printing ◽  
Energy Absorption ◽  
Thermoplastic Elastomers ◽  
Damping Capacity ◽  
Compression Tests ◽  
Wide Range ◽  
Printing Parameters

Additive manufacturing (AM) is a disruptive technology that enables one to manufacture complex structures reducing both time and manufacturing cost. Among the materials commonly used for AM, thermoplastic elastomers (TPE) are of high interest due to their energy absorption capacity, energy efficiency, cushion factor or damping capacity. Previous investigations have exclusively focused on the optimization of the printing parameters of commercial TPE filaments and the structures to analyse the mechanical properties of the 3D printed parts. In the present paper, the chemical, thermal and mechanical properties for a wide range of commercial thermoplastic polyurethanes (TPU) filaments were investigated. For this purpose, TGA, DSC, 1H-NMR and filament tensile strength experiments were carried out in order to determine the materials characteristics. In addition, compression tests have been carried out to tailor the mechanical properties depending on the 3D printing parameters such as: infill density (10, 20, 50, 80 and 100%) and infill pattern (gyroid, honeycomb and grid). The compression tests were also employed to calculate the specific energy absorption (SEA) and specific damping capacity (SDC) of the materials in order to establish the role of the chemical composition and the geometrical characteristics (infill density and type of infill pattern) on the final properties of the printed part. As a result, optimal SEA and SDC performances were obtained for a honeycomb pattern at a 50% of infill density.

Tests on Crepe Soling. III. Water Absorption

1937 ◽  
Vol 10 (3) ◽  
pp. 500-507
Author(s):  
T. H. Messenger ◽  
J. R. Scott
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Direct Evidence ◽  
Pure Water ◽  
Water Soluble ◽  
Solution Viscosity ◽  
Wide Range ◽  
Long Time ◽  
Rate Of Absorption ◽  
Dry Out

Abstract The main results obtained are summarized below: (1) The following observations made by previous workers are confirmed. The absorption by crepe immersed in pure water continues for a very long time, if not indefinitely; the initial rate of absorption and the amount absorbed after long immersion increase rapidly with rise of temperature. The influence of temperature is probably due largely to its effect on the mechanical properties of the rubber, the softening induced by heat facilitating the distension of the rubber. (2) Soling crepes vary enormously in rate of water absorption; this result is ascribable to a variety of causes, as there is direct evidence that water absorption is influenced by the number of plies and the ease of penetration of water between the plies, while the porosity (permeability) of the rubber and its content of water-soluble matter must also come into play; the rigidity of the rubber would be expected to have some influence, although this is not evident in the present experiments. (3) Water absorption does not differentiate sharply between estate and factory-prepared soling crepes, though there are indications that on the average factory crepes absorb water somewhat less rapidly. (4) Among the soling crepes examined, water absorption bears no obvious relationship to mechanical properties or solution viscosity. (5) Addition of solutes to the water in which rubber is immersed reduces the water absorption, and this occurs quantitatively in accordance with the osmotic theory of water absorption. These results indicate that water-absorption tests do not in general yield any information as to the mechanical or physical properties of crepe soling or its mode of manufacture, and are therefore of value only in relation to the water-absorbing properties of the material. Absorption at atmospheric temperatures is so slow that under normal conditions of use it probably does not affect more than a thin surface layer. This layer, however, is responsible for the grip of the soling on the pavement, and if absorption of water influences this gripping power, the control of water-absorbing capacity becomes important. The wide variation at present found between different crepes suggests that an investigation of the factors governing water absorption would enable this property to be closely controlled over a wide range. Penetration of water between the plies, which will occur especially when the soling is somewhat worn, may be more serious than absorption at the outer surface, since water cannot readily dry out from between the plies, and the absorption may therefore become cumulative and lead to weakening of the ply-adhesion.

scholarly journals An Effect of Chromium on Mechanical Properties of the Ni3Al-Based Alloys and Sinters in Compression Tests

2011 ◽  
Vol 56 (4) ◽  
pp. 1007-1014 ◽  
Author(s):  
W. Malec ◽  
K. Rzyman ◽  
M. Czepelak ◽  
A. Wala
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Point Of View ◽  
Compression Tests ◽  
Wide Range ◽  
Cast Alloys ◽  
Intended Use ◽  
Temperature Applications

An Effect of Chromium on Mechanical Properties of the Ni3Al-Based Alloys and Sinters in Compression TestsMechanical properties of the Ni75Al(25-x)Crx cast alloys and sinters were investigated using compression tests conducted within a wide range of compositions and temperature. The alloys and sinters exhibiting the best mechanical properties from a point of view of their intended use as constructional materials suitable for high-temperature applications were selected.

Impact of graphene/graphene oxide on the mechanical properties of cellulose acetate membrane and promising natural seawater desalination

2019 ◽  
Vol 39 (9) ◽  
pp. 794-804
Author(s):  
Nahla Ismail ◽  
Ayman El-Gendi ◽  
Hisham Essawy ◽  
Lara Nezam El-Din ◽  
Kamal Abed ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Cellulose Acetate ◽  
Pure Water ◽  
Natural Seawater ◽  
Cellulose Acetate Membrane ◽  
Permeate Flux ◽  
Salt Rejection ◽  
Wide Range ◽  
Simulated Seawater

Abstract New formulations of cellulose acetate (CA) membrane with graphene (G)/graphene oxide (GO) are suggested and investigated in the present work. This study is intended to find a wide range of conditions for fabricating CA membranes in the presence of some additions of graphene (G), and graphene oxide (GO). The membrane is prepared by phase inversion process. Microscopic investigations for graphene (G), graphene oxide (GO), and prepared membrane were performed by high-resolution transmission electron microscope (HRTEM) and scanning electron microscopy (SEM). The mechanical properties of prepared membranes are determined and evaluated. Permeation tests were performed using natural seawater and simulated seawater to check the prepared membrane performance. The results presented that the permeate flux of M25% CA membranes containing 0.01 wt.% G is the highest flux (57–74 l/m2 h) compared with the neat CA membrane, and the 0.01 wt.% GO-based membranes, while the GO-based membranes were comparable as the neat CA membrane at operating pressures (30–35 bar) and with a feed of 35 g/l NaCl solution. The results showed a remarkable salt rejection of simulated seawater of 95%, and natural seawater with a feed from the Mediterranean Sea displayed 90% salt rejection and accepted pure water flux as well.

Barreling of Solid Cylinders Under Axial Compression

1985 ◽  
Vol 107 (2) ◽  
pp. 138-144 ◽  
Author(s):  
J. K. Banerjee
Keyword(s):  
Compressive Stress ◽  
Dry Friction ◽  
Strain Curve ◽  
Motor Oil ◽  
Compression Tests ◽  
Stress Strain Curve ◽  
Solid Aluminum ◽  
Aspect Ratios ◽  
Wide Range ◽  
Axial Compressive Stress

Axisymmetric compression tests of solid aluminum cylinders, over a wide range of “aspect ratios” (length/diameter) and both under dry as well as lubricated conditions, suggest that the resulting curvature of the “barrel” formed fits closely a circular arc and its radius follows a power law with the true axial compressive stress. The true compressive stress-strain curve, extrapolated from the experimental data in each test, shows that within the variety of lubricants used the Specific Forming Energy is minimum with teflon sheets as dry lubricant, and increases successively with silicon spray, motor oil, and dry friction.

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