scholarly journals Statistical Model for the Mechanical Properties of Al-Cu-Mg-Ag Alloys at High Temperatures

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
A. M. Al-Obaisi ◽  
E. A. El-Danaf ◽  
A. E. Ragab ◽  
M. S. Soliman ◽  
A. N. Alhazaa
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Factorial Design ◽  
High Temperatures ◽  
Statistical Models ◽  
Initial Strain Rate ◽  
Testing Temperature ◽  
Fractional Factorial ◽  
Main Concern ◽  
Strength Deterioration

Aluminum alloys for high-temperature applications have been the focus of many investigations lately. The main concern in such alloys is to maintain mechanical properties during operation at high temperatures. Grain coarsening and instability of precipitates could be the main reasons behind mechanical strength deterioration in these applications. Therefore, Al-Cu-Mg-Ag alloys were proposed for such conditions due to the high stability of Ω precipitates. Four different compositions of Al-Cu-Mg-Ag alloys, designed based on half-factorial design, were cast, homogenized, hot-rolled, and isothermally aged for different durations. The four alloys were tensile-tested at room temperature as well as at 190 and 250°C at a constant initial strain rate of 0.001 s−1, in two aging conditions, namely, underaged and peak-aged. The alloys demonstrated good mechanical properties at both aging times. However, underaged conditions displayed better thermal stability. Statistical models, based on fractional factorial design of experiments, were constructed to relate the experiments output (yield strength and ultimate tensile strength) with the studied process parameters, namely, tensile testing temperature, aging time, and copper, magnesium, and silver contents. It was shown that the copper content had a great effect on mechanical properties. Also, more than 80% of the variation of the high-temperature data was explained through the generated statistical models.

The Effect of Heat Treatment on Mechanical Properties of Car Interior Fabric Used for Injection Molding

2012 ◽  
Vol 532-533 ◽  
pp. 234-237
Author(s):  
Wei Lai Chen ◽  
Ding Hong Yi ◽  
Jian Fu Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Injection Molding ◽  
High Temperatures ◽  
Material Properties ◽  
Injection Molding Process ◽  
Molding Process ◽  
Composite Fabrics

The purpose of this paper is to study the effect of high temperature in injection molding process on mechanical properties of the warp-knitted and nonwoven composite fabrics (WNC)used in car interior. Tensile, tearing and peeling properties of WNC fabrics were tested after heat treatment under120, 140,160,180°C respectively. It was found that, after 140°C heat treatment, the breaking and tearing value of these WNC fabrics are lower than others. The results of this study show that this phenomenon is due to the material properties of fabrics. These high temperatures have no much effect on peeling properties of these WNC fabrics. It is concluded that in order to preserve the mechanical properties of these WNC fabrics, the temperature near 140°C should be avoided possibly during injection molding process.

Comparison Analysis on the Mechanical Properties of HSC and NSC after the Action of High Temperatures

2014 ◽  
Vol 1014 ◽  
pp. 49-52
Author(s):  
Xiao Ping Su
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperatures ◽  
High Strength Concrete ◽  
Elasticity Modulus ◽  
Strain Curve ◽  
Peak Stress ◽  
High Strength ◽  
Peak Strain ◽  
Strength Concrete

With the wide application of high strength concrete in the building construction,the risk making concrete subject to high temperatures during a fire is increasing. Comparison tests on the mechanical properties of high strength concrete (HSC) and normal strength concrete (NSC) after the action of high temperature were made in this article, which were compared from the following aspects: the peak stress, the peak strain, elasticity modulus, and stress-strain curve after high temperature. Results show that the laws of the mechanical properties of HSC and NSC changing with the temperature are the same. With the increase of heating temperature, the peak stress and elasticity modulus decreases, while the peak strain grows rapidly. HSC shows greater brittleness and worse fire-resistant performance than NSC, and destroys suddenly. The research and evaluation on the fire-resistant performance of HSC should be strengthened during the structural design and construction on the HSC buildings.

Oxidation Effects during High Temperature Deformation of CP Ti Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 3678-3683
Author(s):  
Ming Jen Tan ◽  
X.J. Zhu ◽  
S. Thiruvarudchelvan ◽  
K.M. Liew
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
High Temperatures ◽  
Pure Titanium ◽  
Initial Strain Rate ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Uniaxial Tensile ◽  
Commercially Pure Titanium ◽  
Commercially Pure

This work reports the influence of oxidation on the superplasticity of commercially pure titanium at high temperatures. Uniaxial tensile tests were conducted at temperatures in the range 600-800°C with an initial strain rate of 10s-1 to 10s-3. This study shows that oxidization at the surface of the alloy causes oxide film on the surface of commercially pure titanium alloy, and the thickness of oxide film increase with increasing exposure time and temperature. XRD analysis shows that the oxide film consists of TiO2. Because this oxide film is very brittle, it can induce clefts and degrade the ductility of the titanium at high temperatures. The mechanism of the initial clefts was investigated and a model for the cleft initiation and propagation during high temperature tensile test was proposed.

scholarly journals Ageing and Cooling of Hot-Mix-Asphalt during Hauling and Paving—A Laboratory and Site Study

2020 ◽  
Vol 12 (20) ◽  
pp. 8612 ◽  
Author(s):  
Edoardo Bocci ◽  
Emiliano Prosperi ◽  
Volkmar Mair ◽  
Maurizio Bocci
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperatures ◽  
Hot Mix Asphalt ◽  
Prolonged Exposure ◽  
Road Construction ◽  
Temperature Monitoring ◽  
Thermal Camera

In road construction, it can happen that, for different reasons, the time between hot-mix asphalt (HMA) production and paving is extended to some hours. This can be reflected in several problems such as mix cooling and temperature segregation, but also in an extremely severe bitumen ageing due to its prolonged exposure to high temperatures. This paper deals with the investigation of these phenomena both in the laboratory and on site. In particular, the first part of the research aimed at observing the influence of the conditioning time, when the loose HMA is kept in the oven at a high temperature, on the mix properties. The second part focused on the ageing/cooling that happens on site during HMA hauling, as a function of time and type of truck. Temperatures were monitored using a thermal camera and different probes, and gyratory compactor specimens were produced by sampling some HMA from the trucks every 1 h for 3 h. The results showed that HMA stiffness rises if the time when the loose mix stays in the laboratory oven before compaction increases. However, on site, the HMA volumetric and mechanical properties do not change with hauling time up to 3 h, probably because the external material in the truck bed protects the HMA core from the access of oxygen, hindering bitumen oxidation and loss of volatiles. The temperature monitoring highlighted that temperature segregation, after 3 h hauling, can be higher than 30 °C but it can be reduced using insulated truck beds.

High Temperature Composite of Aluminous Cement with Addition of Metakaolin and Ground Bricks Dust

2013 ◽  
Vol 486 ◽  
pp. 406-411 ◽  
Author(s):  
Ondřej Holčapek ◽  
Pavel Reiterman ◽  
Petr Konvalinka
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperatures ◽  
Raw Materials ◽  
Cement Composites ◽  
Basalt Fibers ◽  
Aluminous Cement ◽  
The Common ◽  
Temperature Exposure ◽  
Sufficient Strength

The following article deals with the study of mechanical properties of aluminous cement composites exposure to high temperatures. The newly designed mixtures that resist the action of high temperatures 1000 °C find their application in various fields of industrial production or in the form of fire wall for protection bearing structures. All the mechanical properties such as compressive strength and tensile strength in bending were measured on samples 160x40x40 mm. These samples were exposed to temperatures 600 °C and 1000 °C and one group of samples was reference and stayed in laboratory condition. Aluminous cement unlike the common Portland cement keeps sufficient strength even after high temperature exposure. For ensuring required ductility the basalt fibers were added to the mixture. In an effort to use of secondary raw materials as a replacement for cement as well as a suitable binder was used metakaolin and ground brick dust. Very convenient characteristics of these components are their latent hydraulic potential that makes interesting hydration products.

Factorial Design Approach of Ultra-High Performance Concrete

2013 ◽  
Vol 405-408 ◽  
pp. 2847-2850
Author(s):  
Wu Jian Long ◽  
Wei Lun Wang ◽  
Qi Ling Luo ◽  
Bi Qin Dong
Keyword(s):  
Mechanical Properties ◽  
Factorial Design ◽  
Statistical Models ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Design Approach ◽  
Ultra High Performance Concrete ◽  
Self Consolidating Concrete ◽  
Slump Flow

In order to understand the influence of mixture parameters on ultra-high strength self-consolidating concrete (UHS-SCC) behaviour, an experimental design was carried out in this investigation. In total, 19 SCC mixtures were prepared to determine several key responses that affect the slump flow and compressive strength of UHS-SCC. The statistical models derived from the factorial design approach can be used to quantify the effect of mixture parameters and their coupled effects on fresh and mechanical properties of SCC.

Investigation of Impact Compressive Mechanical Properties of Sandstone After as well as Under High Temperature

2014 ◽  
Vol 33 (6) ◽  
pp. 585-591 ◽  
Author(s):  
Shi Liu ◽  
Jinyu Xu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Critical Temperature ◽  
High Temperatures ◽  
Experimental Studies ◽  
Practical Significance ◽  
Temperature Environment ◽  
Shpb Test ◽  
The Impact ◽  
High Temperature Environment

AbstractConducting experimental studies on the impact compressive mechanical properties of rock under the high temperature environment is of both theoretical value and practical significance to understanding the relationship between the rock under the effect of impact loads and the high temperature environment. Based on the Φ100 mm SHPB and the self-developed Φ100 mm high-temperature SHPB test devices, the impact compressive tests on the sandstone, whether cooling after high temperatures or under real-time high temperatures are carried out. As the test results indicate that since the two high-temperature ways of loading are different from each other, the impact compressive properties of sandstone, after as well as under high temperatures, show different variations along with changes in temperature. Under the effect of the same impact loading rate, there exists a clear critical temperature range in the impact compressive mechanical properties of sandstone after high temperature, and, near the critical temperature, there occurs a significant mutation in the impact compressive mechanical properties. Under high temperatures, however, the impact compressive mechanical properties follow an overall continuity of change except that there are slight fluctuations at individual temperatures.

High temperature mechanical properties of steel bars available in Pakistan

2018 ◽  
Vol 9 (3) ◽  
pp. 203-221 ◽  
Author(s):  
Muhammad Masood Rafi ◽  
Abdul Basit Dahar ◽  
Tariq Aziz
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Ambient Temperature ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Experimental Testing ◽  
Local Market ◽  
Content Type ◽  
Yield Plateau ◽  
Steel Bars

Purpose The purpose of this paper is to present the results of experimental testing of steel rebars at elevated temperatures. Three types of bars available in the local market in Pakistan were used. These data are not available in Pakistan. Design/methodology/approach Three types of bars were used, which included cold-twisted ribbed (CTR), hot-rolled deformed (HRD) and thermo-mechanically treated (TMT) bars. The diameter of the bar of each type was 16 mm. The bars were heated in an electrical furnace at temperatures which were varied from 100°C to 900°C in increment of 100°C. Bars of each type were also tested at ambient temperature as control specimens. The change of strength, strain and modulus of elasticity of the bars at high temperatures were determined. Findings The mechanical properties of the bars were nearly unaffected by the temperatures up to 200°C. CTR bars did not show yield plateau and strain hardening both at ambient and high temperatures. The high temperature yield strength and elastic modulus for all the three types of bars were similar at all temperatures. The yield plateau of both the HRD and TMT bars disappeared at temperatures greater than 300°C. The ultimate strength at high temperature of the HRD and TMT bars was also similar. The behaviours of the HRD and TMT bars changed to brittle beyond 400°C as compared to their behaviours at ambient temperature. The CTR bars exhibited ductile characteristics at failure at all the exposure temperatures relative to their behaviour at ambient temperature. Research limitations/implications The parameters of the paper included the rebar type and heating temperature and the effects of temperature on strength and stiffness properties of the steel bars. Practical implications Building fire incidents have increased in Pakistan. As reinforced concrete (RC) buildings exist in the country in significant numbers, the data related to elevated temperature properties of steel is required. These data are not available in Pakistan presently. The presented paper aims at providing this information for the design engineers to enable them to assess and increase fire resistance of RC structural members. Originality/value The presented paper is unique in its nature in that there is no published contribution to date, to the best of authors’ knowledge, which has been carried out to assess the temperature-dependent mechanical properties of steel reinforcing bars available in Pakistan.

High-Temperature Mechanical Properties of As-Extruded ZK60

2005 ◽  
Vol 488-489 ◽  
pp. 753-758
Author(s):  
Wei Wu ◽  
C.M. Hong ◽  
Li Jia Chen ◽  
Yue Wang ◽  
Lin Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Strain Rate ◽  
Initial Strain Rate ◽  
Offset Yield Strength ◽  
High Temperature Mechanical Properties ◽  
Fracture Behaviors ◽  
Elongation To Failure ◽  
Zk60 Alloy ◽  
High Temperature Tensile

High-temperature tensile and fracture behaviors of as-extruded ZK60 alloy were investigated. It was evident from the experiments that with decreasing temperature and increasing strain rate, the 0.2% offset yield strength and ultimate tensile strength of the alloy increased while the elongation to failure decreased. The flowing stress of as-extruded ZK60 alloy during plastic deformation was proportioned to the reciprocal of temperature. At the initial strain rate of 5×10-4s-1, the calculated active energy at 300°C was about 93.4 kJ/mol.

NICKEL 200

Alloy Digest ◽  
1962 ◽  
Vol 11 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
Temperature Performance ◽  
Nickel 200

Abstract Nickel-200 is a wrought metal combining excellent mechanical properties with corrosion resistance. It retains its strength to an excellent degree at high temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-75. Producer or source: Huntington Alloy Products Division.

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