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Online since: August 2016
Authors: J. Gallego, Vicente Afonso Ventrella, Gillian da S. Crespo, Josiel L. Padilha, Ruis C. Tokimatsu, Celso R. Sokei
The heat affected zone resulting from the welding is pretty much absent and no cracks were detected.
The resultant weld metals contain higher ferrite levels, and have been reported to have inferior properties.
In that case austenite does not have sufficient amount of time to nucleate and grow and this decrease the amount of austenite in weld metal. [6, 7] The present work has been carried out to investigate the influence of the pulse duration and the focus position on neodymium: yttrium aluminum garnet (Nd:YAG) laser welding of UNS S32205 duplex stainless steel and its effect on size and microstructure of fusion zone then, on the mechanical properties.
Moreover, lower pulse duration extended the heat-affect zone.
This is expected because the mechanical properties of steels, in general, are based on its microstructures.[11] As can be seen in Table 2, the microhardness values increased in the weld metal.
The resultant weld metals contain higher ferrite levels, and have been reported to have inferior properties.
In that case austenite does not have sufficient amount of time to nucleate and grow and this decrease the amount of austenite in weld metal. [6, 7] The present work has been carried out to investigate the influence of the pulse duration and the focus position on neodymium: yttrium aluminum garnet (Nd:YAG) laser welding of UNS S32205 duplex stainless steel and its effect on size and microstructure of fusion zone then, on the mechanical properties.
Moreover, lower pulse duration extended the heat-affect zone.
This is expected because the mechanical properties of steels, in general, are based on its microstructures.[11] As can be seen in Table 2, the microhardness values increased in the weld metal.
Online since: April 2008
Authors: K.T. Ramesh, Laszlo J. Kecskes, Suveen N. Mathaudhu, K.T. Hartwig, Q. Wei
Ultrafine and Nanostructured Refractory Metals Processed by SPD:
Microstructure and Mechanical Properties
Q.
The most important factors are the inter-channel angle (Source: website of E.
Factors of SPD temperature, routes, number of turns in HPT or number of passes in ECAE, should be considered.
Mechanical Properties of SPD Processed UFG/NS Refractory Metals Critical and comprehensive reviews on the experimental and theoretical aspects of the mechanical properties of UFG/NS metals have been given by a number of authors and groups[5, 6, 9].
Valdre, "Mechanical properties of nanostructured chromium " Nanostructured materials, vol. 12, pp. 1103-1108, 1999
The most important factors are the inter-channel angle (Source: website of E.
Factors of SPD temperature, routes, number of turns in HPT or number of passes in ECAE, should be considered.
Mechanical Properties of SPD Processed UFG/NS Refractory Metals Critical and comprehensive reviews on the experimental and theoretical aspects of the mechanical properties of UFG/NS metals have been given by a number of authors and groups[5, 6, 9].
Valdre, "Mechanical properties of nanostructured chromium " Nanostructured materials, vol. 12, pp. 1103-1108, 1999
Online since: January 2012
Authors: Yoshikazu Nakai, Kenichi Nakagawa, Kohei Mikami
Macroscopic mechanical properties of the bulk metallic glass (BMG) are affected by the nano-structure such as icosahedral mid-range order and local crystallization; those are considered to be controlled by the cooling rate in casting.
Therefore, the mechanical properties of BMG plates have inhomogeneity in the thickness direction because the cooling rate is highest at the plate surface and it is lowest at the midsection of the plate [15].
Although fatigue cracks initiate from the highest stress concentrated site in homogeneous materials, the crack initiation site in inhomogeneous materials is considered to be controlled not only by the mechanical conditions but also the local mechanical property of the component.
The difference of S-N properties under plane-bending and axial-loading is shown in Fig. 2.
For fatigue tests of BMG plate, however, the inhomogeneity of material should be taken into account in addition to mechanical factors such as the maximum shear stress and shearing strain energy.
Therefore, the mechanical properties of BMG plates have inhomogeneity in the thickness direction because the cooling rate is highest at the plate surface and it is lowest at the midsection of the plate [15].
Although fatigue cracks initiate from the highest stress concentrated site in homogeneous materials, the crack initiation site in inhomogeneous materials is considered to be controlled not only by the mechanical conditions but also the local mechanical property of the component.
The difference of S-N properties under plane-bending and axial-loading is shown in Fig. 2.
For fatigue tests of BMG plate, however, the inhomogeneity of material should be taken into account in addition to mechanical factors such as the maximum shear stress and shearing strain energy.
Online since: October 2010
Authors: An Hua Peng, Zhi Ming Wang
Introduction
Molded parts precision, performance and efficiency are the three main factors that slows down the
development of RPM, in which the four main factors affecting accuracy of FDM parts can be
summarized as follows: ① Errors caused by prototyping system, referring to the localization
accuracy and repeatability of localization accuracy of nozzle motion; ② Principle errors caused
during the triangulation and slicing process; ③ Errors caused by nozzle with a certain diameter;
④ Errors caused by material shrinkage.
Second, with temperature increasing, it gradually changes to high-elastic state and finally to melted state where it shows rheological property, very important property for FDM process.
Extrusion temperature determines the bonding properties of materials, accumulation property, filament material liquidility and extruded filament width.
However, not a fixed value is the width of extrusion filament, subject to influence of many factors such as nozzle diameter, layer thickness, extrusion speed, scanning speed, extrusion temperature, envelope temperature, coefficient of adhesion, shrinkage rate, and so on.
In addition, there also exist other factors affecting parts accuracy such as principle error, error caused by numerical control system and error caused by material shrinkage etc..
Second, with temperature increasing, it gradually changes to high-elastic state and finally to melted state where it shows rheological property, very important property for FDM process.
Extrusion temperature determines the bonding properties of materials, accumulation property, filament material liquidility and extruded filament width.
However, not a fixed value is the width of extrusion filament, subject to influence of many factors such as nozzle diameter, layer thickness, extrusion speed, scanning speed, extrusion temperature, envelope temperature, coefficient of adhesion, shrinkage rate, and so on.
In addition, there also exist other factors affecting parts accuracy such as principle error, error caused by numerical control system and error caused by material shrinkage etc..
Online since: December 2014
Authors: Jorge de Brito, Miguel Bravo, Jorge Pontes, Luís Evangelista
However, some recent researches indicate that the use of fine RA in concrete may be viable, since it did not lead to a significant loss of the properties, both in mechanical and durability terms.
However, the scale of the strength decrease depends on various factors.
This was expected since, in the water absorption analysis, influenced by the same factors, the same trend occurred.
Pedro, Mechanical properties of concrete produced with recycled coarse aggregates - Influence of the use of superplasticizers, Construction and Building Materials 44, 3013, pp. 101-109
Neville, Properties of concrete, 4th ed. 1995, 844 p
However, the scale of the strength decrease depends on various factors.
This was expected since, in the water absorption analysis, influenced by the same factors, the same trend occurred.
Pedro, Mechanical properties of concrete produced with recycled coarse aggregates - Influence of the use of superplasticizers, Construction and Building Materials 44, 3013, pp. 101-109
Neville, Properties of concrete, 4th ed. 1995, 844 p
Online since: March 2011
Authors: Kamran Pazand, Hawshin Feizi
The geometrical properties of the billet, die and punch were listed in Tab. 1.
Physical and mechanical properties of the billet used in the simulations were recorded in Tab. 2.
Tab. 1 Geometrical properties of the billet, the die and the punch.
Tab. 2 Physical and mechanical properties of the billet.
These ultrasonic process are basically for specific working conditions and therefore virtually factors of ultrasonic process have complex effects on extrusion .This means that experimental data from one existing ultrasonic factors cannot be reliably used to predict the exact extrusion behavior of another; and simulation is the only affordable means the designer has at his/her disposal in the design phase.
Physical and mechanical properties of the billet used in the simulations were recorded in Tab. 2.
Tab. 1 Geometrical properties of the billet, the die and the punch.
Tab. 2 Physical and mechanical properties of the billet.
These ultrasonic process are basically for specific working conditions and therefore virtually factors of ultrasonic process have complex effects on extrusion .This means that experimental data from one existing ultrasonic factors cannot be reliably used to predict the exact extrusion behavior of another; and simulation is the only affordable means the designer has at his/her disposal in the design phase.
Online since: July 2014
Authors: Yun Wei Guo, Wen Hua Xu, Yang Jiang, Hui Hui Liu, Jia Yu Xu, Zhan Qiang Gao, Li Zhu Liu, Wei Wei Cui
This work describes the preparation and the properties of poly(vinylidene fluoride) (PVDF) porous membranes.
Poly(vinylidene fluoride) (PVDF) as one of the attractive membrane materials used in water treatment field processes many outstanding properties, including excellent chemical resistance, good mechanical properties, and having excellent resistance to most corrosive chemicals and organic compounds [5-7].
Intrinsic chemical composition is not the only factor affecting the suitability of the membrane, the morphological properties, too, play a significant role.
By selecting the correct modified material and the fabrication parameters, the morphology and the properties of the membrane can be varied, and then the membrane can be valuable for different application.
Meanwhile, the porous structure can act as a mechanical support.
Poly(vinylidene fluoride) (PVDF) as one of the attractive membrane materials used in water treatment field processes many outstanding properties, including excellent chemical resistance, good mechanical properties, and having excellent resistance to most corrosive chemicals and organic compounds [5-7].
Intrinsic chemical composition is not the only factor affecting the suitability of the membrane, the morphological properties, too, play a significant role.
By selecting the correct modified material and the fabrication parameters, the morphology and the properties of the membrane can be varied, and then the membrane can be valuable for different application.
Meanwhile, the porous structure can act as a mechanical support.
Online since: November 2012
Authors: Takayoshi Nakano, Shinji Ogawa, Dorian Cretin, Ryoichi Suetoshi
To evaluate the bone mechanical characteristics, it is essential to investigate the elastic properties of cortical bone.
However, one problem with artificial hip joints lies in the fact that, because of the differences in mechanical properties between the implant and bone, a stress shielding occurs which is known to lead to bone loss [1].
However, there have been few studies concerning the change of elastic properties in bone surrounding implants.
For example, the Speed of Sound (SOS), at which ultrasounds propagate inside bone, is known to reflect such properties [8].
The elastic properties of the cortical bone are important to the assessment of the mechanical function of bone.
However, one problem with artificial hip joints lies in the fact that, because of the differences in mechanical properties between the implant and bone, a stress shielding occurs which is known to lead to bone loss [1].
However, there have been few studies concerning the change of elastic properties in bone surrounding implants.
For example, the Speed of Sound (SOS), at which ultrasounds propagate inside bone, is known to reflect such properties [8].
The elastic properties of the cortical bone are important to the assessment of the mechanical function of bone.
Online since: June 2013
Authors: Gerhard Hirt, Markus Bambach, Thomas Henke
Excellent mechanical properties needed for gearing components e.g. high load capacity and high fatigue resistance depend on a fine homogeneous microstructure in the final product.
Additionally, the final product would show poor mechanical properties due to its inhomogeneous microstructure at room temperature [3].
Determination of a microstructure-based material model The microstructure evolution mechanisms occurring in hot forging processes such as dynamic recrystallization and grain growth affect the resulting microstructure and hence the mechanical-technological properties of a material in a decisive manner.
Figure 3), the thermal material properties were calculated using CALPHAD methods.
Hirt, Experimental Uncertainties affecting the Accuracy of Stress-Strain Equations by the Example of a Hensel-Spittel Approach, in: G.
Additionally, the final product would show poor mechanical properties due to its inhomogeneous microstructure at room temperature [3].
Determination of a microstructure-based material model The microstructure evolution mechanisms occurring in hot forging processes such as dynamic recrystallization and grain growth affect the resulting microstructure and hence the mechanical-technological properties of a material in a decisive manner.
Figure 3), the thermal material properties were calculated using CALPHAD methods.
Hirt, Experimental Uncertainties affecting the Accuracy of Stress-Strain Equations by the Example of a Hensel-Spittel Approach, in: G.
Online since: November 2010
Authors: Bo Zhao, Jin Xue Xue
Its mechanical properties are shown in Table 2.
Table 2 Mechanical properties of nano ZrO2 Parameters Vickers hardness [GPa] Elasticity modulus [GPa] Flexural strength [MPa] Fracture toughness [MPa·m1/2] Density [g·cm-3] Pyroconductivity [m·K] Specific heat [Kg/K] Poisson's ratio Value 12 360 700 9.3 6.2 2.1 610 0.27 Grinding Temperature Testing Scheme Infrared radiation and infrared thermography method are sensitive to environmental impact and other factors, so the artificial thermocouple wire clip temperature measurement method was used in our experiments as shown in Fig.2 [2-3].
The wheel speed and dressing depth are secondary influencing factors.
Feed rate and ultrasonic power are the most important factors influencing the grinding temperature.
Wheel speed and dressing depth are secondary factors.
Table 2 Mechanical properties of nano ZrO2 Parameters Vickers hardness [GPa] Elasticity modulus [GPa] Flexural strength [MPa] Fracture toughness [MPa·m1/2] Density [g·cm-3] Pyroconductivity [m·K] Specific heat [Kg/K] Poisson's ratio Value 12 360 700 9.3 6.2 2.1 610 0.27 Grinding Temperature Testing Scheme Infrared radiation and infrared thermography method are sensitive to environmental impact and other factors, so the artificial thermocouple wire clip temperature measurement method was used in our experiments as shown in Fig.2 [2-3].
The wheel speed and dressing depth are secondary influencing factors.
Feed rate and ultrasonic power are the most important factors influencing the grinding temperature.
Wheel speed and dressing depth are secondary factors.