Microstructure and Properties of Aluminium Processed by Constrained Groove Pressing

2008 ◽  
Vol 584-586 ◽  
pp. 535-540 ◽  
Author(s):  
Jozef Zrník ◽  
Tomas Kovarik ◽  
Miroslav Cieslar
Keyword(s):  
Tensile Strength ◽  
Electron Back Scatter Diffraction ◽  
Substantial Impact ◽  
Transmission Electron ◽  
Purity Aluminium ◽  
Commercial Purity Aluminium ◽  
The Impact ◽  
The Relationship ◽  
Strength And Ductility ◽  
Strain Increase

In this study, the relationship between the structure and properties of commercial purity aluminium (AW-1199) was investigated by applying constrained groove pressing (CGP) method. The refinement of the coarse grain aluminium microstructure to submicrocrystalline size by large plastic strain at room temperature defined. The impact of various strains upon microstructure changes is investigated using transmission electron microscopy (TEM) and electron back scatter diffraction (EBSD). A mixture of subgrains produced by grains subdivision and polygonized subgrains formed locally due to dynamic recovery was found in the deformed aluminium. The tensile properties and resulting hardness are related to microstructural evolution induced by CGP. A substantial impact of straining upon the increasing in tensile strength was observed after the first pass. Further strain increase had an insignificant effect on tensile strength but was accompanied by ductility loss. The post deformation annealing effect was then explored with aim to increase the ductility. The results indicate that changes in strength and ductility may be related to formation of a bimodal structure.

Effect of Processing Conditions on the Microstructure Development during Constrained Groove Pressing of Aluminium

2014 ◽  
Vol 783-786 ◽  
pp. 331-337 ◽  
Author(s):  
Jozef Zrník ◽  
Libor Kraus ◽  
Miroslav Cieslar ◽  
Peter Sláma
Keyword(s):  
Tensile Strength ◽  
Room Temperature ◽  
Dynamic Recovery ◽  
Processing Conditions ◽  
Structure And Properties ◽  
Transmission Electron ◽  
The Impact ◽  
The Relationship ◽  
Strength And Ductility ◽  
Strain Increase

In this study, the relationship between the structure and properties of commercial purityaluminium (AW-1199) was investigated by applying constrained groove pressing (CGP) method.The refinement of the coarse grain aluminium microstructure to submicrocrystalline size by largeplastic strain at room temperature defined. The impact of various strains upon microstructurechanges is investigated using transmission electron microscopy (TEM) and electron back scatterdiffraction (EBSD). A mixture of subgrains produced by grains subdivision and polygonizedsubgrains formed locally due to dynamic recovery was found in the deformed aluminium. Thetensile properties and resulting hardness are related to microstructural evolution induced by CGP. Asubstantial impact of straining upon the increasing in tensile strength was observed after the firstpass. Further strain increase had an insignificant effect on tensile strength but was accompanied byductility loss. The post deformation annealing effect was then explored with aim to increase theductility. The results indicate that changes in strength and ductility may be related to formation of abimodal structure.

Structure Development and Deformation Behaviour of Pure Aluminium Processed by Constrained Groove Pressing

2014 ◽  
Vol 794-796 ◽  
pp. 882-887
Author(s):  
Jozef Zrník ◽  
Miroslav Cieslar ◽  
Peter Slama
Keyword(s):  
Tensile Strength ◽  
Deformation Behaviour ◽  
Electron Back Scatter Diffraction ◽  
Pure Aluminium ◽  
Deformation Method ◽  
Substantial Impact ◽  
Thin Foils ◽  
Commercial Purity Aluminium ◽  
Deformation Step ◽  
The Impact

In this study, the relationship between the structure and properties of commercial purity aluminium alloy A1199 was investigated by applying constrained groove pressing (CGP) deformation method. The refinement of the coarse grain aluminium (Al) microstructure to sub microcrystalline size by large plastic strain at room temperature defined. The impact of various strains upon microstructure changes is investigated using transmission electron microscopy (TEM of thin foils) and electron back scatter diffraction (EBSD). A mixture of subgrains produced by grains subdivision and polygonized subgrains formed locally due to dynamic recovery was found in the deformed aluminium structure. The tensile properties and resulting hardness are related to microstructural evolution induced by constrained groove pressing deformation. A substantial impact of straining upon the increasing in tensile strength was observed after the first deformation step (first pass) Further strain increase had an insignificant effect on tensile strength but was accompanied by ductility loss. The post deformation annealing effect was then explored with aim to increase the ductility. The results indicate that changes in strength and ductility may be related to formation of a bimodal structure in deformed plates.

Comparison of Shear, Compressive and Tensile Characteristics of Cast Irons

1973 ◽  
Vol 15 (1) ◽  
pp. 53-60 ◽  
Author(s):  
R. D. Adams ◽  
M. A. O. Fox
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Design Criteria ◽  
Matrix Structure ◽  
Proof Stress ◽  
Cast Irons ◽  
The Matrix ◽  
The Relationship ◽  
Graphite Inclusions ◽  
Strength And Ductility

Cast irons were produced with variations in the quantity and shape of the free graphite inclusions and in the matrix structure to investigate the relationship between the shear, compressive and tensile mechanical properties. Differences were observed which may have a significant effect on design criteria for cast irons. For example, the ratio of shear to tensile strengths decreased from about 1·25 to 0·577 and the ratio of 0·1 per cent proof stress in compression to that in tension decreased from approximately 2 to 11 as the tensile strength (and ductility) were increased.

scholarly journals Energizing Intention to Visit Rural Destinations: How Social Media Disposition and Social Media Use Boost Tourism Through Information Publicity

2021 ◽  
Vol 12 ◽  
Author(s):  
Yunfeng Shang ◽  
Khalid Mehmood ◽  
Yaser Iftikhar ◽  
Atif Aziz ◽  
Xuedan Tao ◽  
...  
Keyword(s):  
Social Media ◽  
Media Use ◽  
Subjective Norms ◽  
Mediating Effect ◽  
Social Media Use ◽  
Substantial Impact ◽  
Time Lagged ◽  
Rural Destinations ◽  
The Impact ◽  
The Relationship

This study aimed to examine the impact of information publicity on the intention of tourists to visit rural destinations in developing countries. Based on the theory of planned behavior (TPB), we examined the indirect effect of information publicity on intention to visit via subjective norms and further investigated the moderating effect of social media disposition and social media use. The study used data from a time-lagged design with three waves which supported the hypothesized model. The findings revealed that information publicity has an influence on the intention of tourists to visit through the mediating effect of subjective norms. Moreover, the social media disposition strengthened the relationship between information publicity and subjective norms. Furthermore, social media use positively moderated the relationship between subjective norms and intention to visit. Besides the core TPB constructs, the added variables indeed exerted a substantial impact on the visit intention of tourists. The study contributed to the tourism-related literature on social media and the practical implications were discussed.

scholarly journals Modulation of Multiple Precipitates for High Strength and Ductility in Al-Cu-Mn Alloy

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7383
Author(s):  
Linxiang Liu ◽  
Zhijun Wang ◽  
Qingfeng Wu ◽  
Zhongsheng Yang ◽  
Kexuan Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
High Strength ◽  
Mechanical Behaviors ◽  
High Tensile Strength ◽  
Transmission Electron ◽  
Evolution Pattern ◽  
Elongation To Failure ◽  
High Elongation ◽  
Strength And Ductility

The category and morphology of precipitates are essential factors in determining the mechanical behaviors of aluminum alloys. It is a great challenge to synthetically modulate multiple precipitates to simultaneously improve strength and ductility. In the present work, by optimizing the precipitations of the GP zone, θ’-approximant and θ’ phase for an Al-Cu-Mn alloy, a high tensile strength of 585 MPa with large elongation of 12.35% was achieved through pre-deformation and aging. The microstructure evolution pattern was revealed by detailed characterizations of scanning electron microscopy and transmission electron microscopy. It was found that such high tensile strength of the samples was due to a combination of strengthening by the high density of dispersive fine precipitates and dislocations, and the high elongation to failure was primarily attributed to the multimodal precipitates and elimination of precipitation-free zones along the grain boundaries. The strategy proposed here is a promising way of preparing ultra-strong Al-Cu-Mn alloys.

On the Microstructure and Fracture Surface of Bainite in JIS SK5 Steel

2006 ◽  
Vol 118 ◽  
pp. 451-456 ◽  
Author(s):  
Meng Yin Tu ◽  
Wen Hsiung Wang ◽  
Yung Fu Hsu
Keyword(s):  
Electron Microscopy ◽  
Fracture Surface ◽  
Brittle Failure ◽  
Lower Bainite ◽  
Electron Back Scatter Diffraction ◽  
Cleavage Facet ◽  
Transmission Electron ◽  
Bainite Structure ◽  
Upper Bainite ◽  
The Impact

The microstructure and fracture surface of bainite in JIS SK5 steel have been investigated using transmission electron microscopy (TEM) and electron back-scatter diffraction (EBSD) in this study. Specimens were austenitized at 880 for 30 min and then austempered at 300 and 400 for 1hr, as a result, lower bainite and upper bainite were formed, respectively. The lower bainite phase consists of plate-like bainitic ferrites and embedded cementite platelets, the cementite precipitated unidirectionally at an angle of 55 to 60 deg deviated from the long axes of the ferrites; in addition, the upper bainite phase consists of a parallel array of ferrite laths and discrete cementite layers sandwiched between them. Both the bainite structures have the same ferrite/cementite orientation relationship, which is close to that of the Bagaryatskii relation. The impact fractographs of lower and upper bainite structures exhibit brittle failure with cleavage facets, of which the size is correlated with the width of the bainite sheaves. Moreover, the crystallographic orientation of cleavage facets has been determined directly by EBSD. The results showed that the cleavage facet planes of lower bainite structure are close to the {001} plane of ferrite, and they were close to the {001}, {112} and {123} planes of ferrite for the upper bainite structure.

scholarly journals Impact of PVC mixtures of the Electrical Conduit on the Physical Properties: تأثير خلطات البي في سي لصناعة القنوات الكهربائية على الخواص الفيزيائية

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
AbdelHamid M.S. Esmail
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Correlation Coefficients ◽  
Strong Relationship ◽  
Chemical Components ◽  
Random Samples ◽  
Long Time ◽  
The Impact ◽  
The Relationship ◽  
Soft Point

The use of PVC mixtures in the manufacturing of electrical conduit has been employed for a long time along with other materials. In this study, the impact of changing the ratio of the components of the PVC mixtures on the physical properties of the electrical conduit was investigated. The emphasis was placed on three properties: Density, Tensile Strength and Soft Point. The application of the electrical conduit controls the types of materials and their percentages. Physical properties of the PVC products are the most important factors that help to choose compared with other materials. These properties change with the change of the chemical components of the PVC mixture. The study discussed how to enhance and improve these properties by controlling the proportions of some substances in the PVC mixtures. This article aims to demonstrate the strong relationship between PVC polymer, calcium and stabilizers and the physical properties of the electrical conduit. The focus concentrated on three components in the mixture and three physical properties. Random samples were taken to calculate the average percentages of the components in the mixtures. Various tools and several statistical methods were used such as correlation coefficients and scatter charts to prove the relationship between the ratios of the materials and the respective properties. The correlation coefficients between the PVC polymer, stabilizers, calcium, and the density, tensile strength, vicat soft points were (0.92, 0.83, 0.82) respectively. Decreasing the PVC polymer by (17.1%) has caused an increase in the density of the conduit by (2%). Finally, the physical properties of PVC mixtures could be improved by changing component ratios to reach the optimized mixture for the specific application, taking into account other competitive issues such as the final price of the product, environmental impact, and other issues.

scholarly journals Development of Methods to Improve the Mechanical Performance of Coated Grid-Like Non-Crimp Fabrics for Construction Applications

2019 ◽  
Vol 27 (1(133)) ◽  
pp. 51-58 ◽  
Author(s):  
Lars Hahn ◽  
Steffen Rittner ◽  
Dominik Nuss ◽  
Moniruddoza Ashir ◽  
Chokri Cherif
Keyword(s):  
Tensile Strength ◽  
Mechanical Performance ◽  
Coating Process ◽  
Ultrasonic Vibrations ◽  
Coating Agent ◽  
Industry Standard ◽  
Machine Setting ◽  
The Impact ◽  
The Relationship ◽  
Setting Parameters

This paper presents investigations aiming to improve the impregnation of a coating agent and thus increase the mechanical performance of geogrids, especially grid-like non-crimp fabrics (NCF) consisting of carbon fiber heavy tows (CFHT). The squeezing process is industry standard, but the relationship between the machine setting parameters (squeezing pressure and hardness of squeeze roll surface) and the impact on the tensile strength of grid-like NCF is still unexplored. The setting parameters evaluated lead to an increase in tensile strength of up to 10% compared to grid-like NCF coated without the squeezing process. Additionally the first insights into the coating process supported by ultrasonic vibrations based on CFHT single yarns are provided. It is shown that the tensile strength of treated CFHT can be increased by up to 12%, in comparison to CFHT coated without ultrasonic vibrations.

The Strength and Ductility of Ice Under Tension

1988 ◽  
Vol 110 (2) ◽  
pp. 187-191 ◽  
Author(s):  
R. W. Lee ◽  
E. M. Schulson
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Size Effects ◽  
Strain Rates ◽  
The Relationship ◽  
Strength And Ductility ◽  
Grain Size Effects

Tensile experiments have been performed on aggregates of equiaxed and randomly oriented ice Ih of varying grain size (1.4 to 7.9 mm) at −10°C at two strain rates, 10−3 s−1 and 10−7 s−1. At both rates, which were held constant using “feed-back” control, the tensile strength decreased with increasing grain size. This result confirms earlier work on grain size effects in which the rate randomly varied (from 0.6 × 10−6 s−1 to 3 × 10−6 s−1) from test to test. At the higher rate the ice is brittle over the complete range of grain size and its strength is given by the relationship σf = σo + kd−1/2 where σo = 0.51 MPa and k = 0.03 MPa m1/2. At the lower rate the ice is ductile over the same range of grain size and its strength is given by the relationship σf = Kd−1/2 where K = 0.050 MPa m1/2. These effects are explained quantitatively in terms of the nucleation and propagation of cracks.

scholarly journals Effect of Isothermal Transformation Times below Ms and Tempering on Strength and Toughness of Low-Temperature Bainite in 0.53 C Bainitic Steel

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2418
Author(s):  
Enzuo Liu ◽  
Qiangguo Li ◽  
Sufyan Naseem ◽  
Xuefei Huang ◽  
Weigang Huang
Keyword(s):  
Low Temperature ◽  
Impact Toughness ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Isothermal Transformation ◽  
Electron Back Scatter Diffraction ◽  
Bainitic Steel ◽  
Transmission Electron ◽  
The Impact ◽  
Tempering Process

This study aims to investigate the microstructures, strength, and impact toughness of low-temperature bainite obtained by isothermal transformation at temperature below Ms (Martensite Starting temperature) for different times and tempering process in 0.53 C wt% bainitic steel. By using the optical microscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), electron back scatter diffraction (EBSD), and mechanical property test, it was found that the microstructures after heat treatment consist of small amounts of martensite, fine bainite, and film retained austenite. After tempered at 250 °C for 2 h, the volume fraction of retained austenite (10.9%) in the sample treated by isothermal transformation at 220 °C for three hours is almost the same as that of the sample without tempering. In addition, the retained austenite fraction decreases with the increase of holding times and is reduced to 6.8% after holding for 15 h. The ultimate tensile strength (1827 MPa), yield strength (1496 MPa), total elongations (16.1%), and impact toughness (up to 58 J/cm2) were obtained by isothermal transformation at 220 °C for three hours and tempered at 250 °C. Whereas, the impact toughness of sample without tempering is 28 J/cm2. After holding for 15 h, the impact toughness raises to 56 J/cm2, while the ductility and strength decreases. These results indicate that the tempering process is helpful to improve the impact toughness of low-temperature bainite.

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