scholarly journals Elevated Temperature Tensile Creep Behavior of Aluminum Borate Whisker-Reinforced Aluminum Alloy Composites (ABOw/Al–12Si)

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1217
Author(s):  
Yameng Ji ◽  
Yanpeng Yuan ◽  
Weizheng Zhang ◽  
Yunqing Xu ◽  
Yuwei Liu
Keyword(s):  
Elevated Temperature ◽  
Creep Test ◽  
Load Transfer ◽  
Elevated Temperatures ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Fracture Mechanisms ◽  
Transfer Model ◽  
Unreinforced Alloy ◽  
The Matrix

In order to evaluate the elevated temperature creep performance of the ABOw/Al–12Si composite as a prospective piston crown material, the tensile creep behaviors and creep fracture mechanisms have been investigated in the temperatures range from 250 to 400 °C and the stress range from 50 to 230 MPa using a uniaxial tensile creep test. The creep experimental data can be explained by the creep constitutive equation with stress exponents of 4.03–6.02 and an apparent activation energy of 148.75 kJ/mol. The creep resistance of the ABOw/Al–12Si composite is immensely improved by three orders of magnitude, compared with the unreinforced alloy. The analysis of the ABOw/Al–12Si composite creep data revealed that dislocation climb is the main creep deformation mechanism. The values of the threshold stresses are 37.41, 25.85, and 17.36 at elevated temperatures of 300, 350 and 400 °C, respectively. A load transfer model was introduced to interpret the effect of whiskers on the creep rate of this composite. The creep test data are very close to the predicted values of the model. Finally, the fractographs of the specimens were analyzed by Scanning Electron Microscope (SEM), the fracture mechanisms of the composites at different temperatures were investigated. The results showed that the fracture characteristic of the ABOw/Al–12Si composite exhibited a macroscale brittle feature range from 300 to 400 °C, but a microscopically ductile fracture was observed at 400 °C. Additionally, at a low tensile creep temperature (300 °C), the plastic flow capacity of the matrix was poor, and the whisker was easy to crack and fracture. However, during tensile creep at a higher temperature (400 °C), the matrix was so softened that the whiskers were easily pulled out and interfacial debonding appeared.

Experimental Investigation of Ti-6Al-4V with a Biaxial Tensile Test Setup at Elevated Temperature

2014 ◽  
Vol 622-623 ◽  
pp. 273-278 ◽  
Author(s):  
Marion Merklein ◽  
Sebastian Suttner ◽  
Adam Schaub
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Advanced Materials ◽  
Uniaxial Tensile ◽  
Plastic Yielding ◽  
Characterization Methods ◽  
Specific Strength ◽  
Biaxial Tensile ◽  
Stress States

The requirement for products to reduce weight while maintaining strength is a major challenge to the development of new advanced materials. Especially in the field of human medicine or aviation and aeronautics new materials are needed to satisfy increasing demands. Therefore the titanium alloy Ti-6Al-4V with its high specific strength and an outstanding corrosion resistance is used for high and reliable performance in sheet metal forming processes as well as in medical applications. Due to a meaningful and accurate numerical process design and to improve the prediction accuracy of the numerical model, advanced material characterization methods are required. To expand the formability and to skillfully use the advantage of Ti-6Al-4V, forming processes are performed at elevated temperatures. Thus the investigation of plastic yielding at different stress states and at an elevated temperature of 400°C is presented in this paper. For this reason biaxial tensile tests with a cruciform shaped specimen are realized at 400°C in addition to uniaxial tensile tests. Moreover the beginning of plastic yielding is analyzed in the first quadrant of the stress space with regard to complex material modeling.

Dynamic Behavior of Metals Under Tensile Impact—Part 1: Elevated Temperature Tests

1970 ◽  
Vol 37 (3) ◽  
pp. 765-770 ◽  
Author(s):  
A. B. Schultz
Keyword(s):  
Elevated Temperature ◽  
Mechanical Behavior ◽  
Dynamic Behavior ◽  
Dynamic Loading ◽  
Elevated Temperatures ◽  
Uniaxial Tensile ◽  
Tensile Impact ◽  
Wide Range

The mechanical behavior of metals subjected to uniaxial tensile impact at elevated temperatures is reported. Tests were conducted on annealed 1100 aluminum at 200, 350, 550, and 800 deg F; annealed 2024 aluminum at 200, 450, and 600 deg; and annealed C1010 steel at 430, 700, 1050, and 1400 deg F. The materials exhibit a wide range of dynamic behavior, including some in which the stress required to produce a given level of strain is significantly lowered by dynamic loading. The ratios of the dynamic ultimate stresses to the static are found to range from 0.71–6.0.

Experimental Study on the Mechanical Property and Forming Limit of Magnesium Sheet at Elevated Temperatures

2009 ◽  
Author(s):  
Y. Huang ◽  
J. Huang ◽  
J. Cao
Keyword(s):  
Elevated Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Tensile Tests ◽  
Alloy Sheet ◽  
Dome Height ◽  
Forming Limit ◽  
Uniaxial Tensile ◽  
Magnesium Sheet

Magnesium alloy sheet has received increasing attention in automotive and aerospace industries. It is widely recognized that magnesium sheet has a poor formability at room temperature. While at elevated temperature, its formability can be dramatically improved. Most of work in the field has been working with the magnesium sheet after annealed around 350°C. In this paper, the as-received commercial magnesium sheet (AZ31B-H24) with thickness of 2mm has been experimentally studied without any special heat treatment. Uniaxial tensile tests at room temperature and elevated temperature were first conducted to have a better understanding of the material properties of magnesium sheet (AZ31B-H24). Then, limit dome height (LDH) tests were conducted to capture forming limits of magnesium sheet (AZ31B-H24) at elevated temperatures. An optical method has been introduced to obtain the stress-strain curve at elevated temperatures. Experimental results of the LDH tests were presented.

Synchrotron x-ray Study of Elastic Phase Strains in the Bulk of an Externally Loaded Cu/Mo Composite

1999 ◽  
Vol 590 ◽  
Author(s):  
A. Wanner ◽  
D.C. Dunand
Keyword(s):  
Plastic Deformation ◽  
Load Transfer ◽  
Tensile Deformation ◽  
Copper Matrix ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Rays ◽  
Synchrotron Source ◽  
Peak Broadening ◽  
The Matrix

ABSTRACTHigh-energy, high-flux x-rays from a third-generation synchrotron source were used to measure average elastic strains in the bulk of 1.5 mm thick composites consisting of a copper matrix reinforced with 7.5 vol.% molybdenum particles. From the evolution of lattice strains in both phases during uniaxial tensile deformation, the internal load transfer between phases and reinforcement damage were characterized during elastic and plastic deformation of the composite. The graininess of the diffraction rings, which is related to the Bragg peak broadening, was quantified as a function of applied stress and related to plastic deformation in the matrix.

Synchrotron X-ray Diffraction Measurement of Reinforcement Strains in Uniaxially Stressed Bulk Metallic Glass Composites

2001 ◽  
Vol 678 ◽  
Author(s):  
Dorian K. Balch ◽  
Ersan Üstündag ◽  
David C. Dunand
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Load Transfer ◽  
High Energy ◽  
Uniaxial Tensile ◽  
Diffraction Measurement ◽  
X Rays ◽  
Glass Composites ◽  
Bulk Metallic Glass Composites ◽  
The Matrix

AbstractHigh-energy synchrotron x-rays were used to measure internal reinforcement strains in bulk metallic glass composites containing tungsten or tantalum particles during in-situ uniaxial tensile loading. Load transfer from the matrix to the stiffer but weaker particles was characterized in both their elastic and plastic regimes and compared to theoretical predictions.

Tensile Creep Damage and Rupture of Al2O3-SiO2(sf)/AZ91 Composite

2011 ◽  
Vol 55-57 ◽  
pp. 257-261
Author(s):  
Jun Tian ◽  
Shou Yan Zhong
Keyword(s):  
Creep Resistance ◽  
Load Transfer ◽  
Fiber Composite ◽  
Fiber Quality ◽  
Matrix Alloy ◽  
Short Fiber ◽  
Grain Boundary Sliding ◽  
Tensile Creep ◽  
Aluminum Silicate ◽  
The Matrix

Constant stress tensile creep tests were conducted on an AZ 91–25 vol.% Al2O3-SiO2short fiber composite and on an unreinforced AZ 91 matrix alloy. The creep resistance of the reinforced material is shown to be considerably improved compared with the matrix alloy. The creep strengthening arises mainly from the effective load transfer between plastic flow in the matrix and the fibers. Microstructural investigations by SEM revealed good fiber–matrix interface bonding during creep exposure. Short fibers have a great function in load bearing and load transfer, and greatly hinder the dislocation movement, thus enhancing the creep resistance of the composite. Damage and multiple rupture of aluminum silicate short fiber, quality of the interface combination between aluminum silicate short fiber reinforcement and the matrix, are two important factors of the creep deformation microstructure process control of Al2O3-SiO2(sf)/AZ91 composite. The creep mechanism of the composite is dislocation and grain boundary sliding control.

Thermal and Loading Effects on Mechanical Properties of a Hot Isostatically Pressed Si3N4

1994 ◽  
Author(s):  
Jagannathan Sankar ◽  
Jayant Neogi ◽  
Suneeta S. Neogi ◽  
Marvln T. Dixie ◽  
Ranji Vaidyanathan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silicon Nitride ◽  
Elevated Temperatures ◽  
Heat Engine ◽  
Tensile Tests ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Creep Tests ◽  
Loading Effects

The effect of thermal soaking on the mechanical properties of a candidate material for advanced heat engine applications namely, hot isostatically pressed (HIPed) silicon nitride (GTEPY6) are reported here. Pure uniaxial tensile tests conducted at room and at elevated temperatures indicated that the tensile strength of this material dropped significantly after 1000°C. The residual tensile strength of PY6 material after thermal soaking at 1200° and 1300°C was also investigated. Test results showed that thermal soaking at 1200° and 1300°C increased the residual tensile strength. The thermal soaking time had a greater effect on the residual tensile strength at 1300°C. Tensile creep tests performed at 1200° and 1300°C showed that the steady state creep rate was influenced by both the temperature and the applied stress. The higher stress exponent in HIPed as compared to a sintered silicon nitride shows higher creep resistance in the case of HIPed materials.

scholarly journals Assessment of Thermal Stresses in Asphalt Mixtures at Low Temperatures Using the Tensile Creep Test and the Bending Beam Creep Test

2019 ◽  
Author(s):  
Marek Pszczola ◽  
Mariusz Jaczewski ◽  
Cezary Szydlowski
Keyword(s):  
Thermal Stress ◽  
Low Temperature ◽  
Creep Test ◽  
Thermal Stresses ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Tensile Creep ◽  
Rheological Parameters ◽  
Uniaxial Tensile ◽  
Failure Temperature

Thermal stresses belong to the leading factors that influence low-temperature cracking behavior of asphalt pavements. During winter, when temperature drops to significantly low values, tensile thermal stresses develop as a result of pavement contraction. Creep test methods can be suitable for the assessment of low-temperature properties of asphalt mixtures. To evaluate the influence of creep test methods on the obtained low-temperature properties of asphalt mixtures, three point bending and uniaxial tensile creep tests were applied and the master curves of stiffness modulus were analyzed. On the basis of creep test results, rheological parameters describing elastic and viscous properties of the asphalt mixtures were determined. Thermal stresses were calculated and compared to tensile strength of the material to obtain the failure temperature of the analyzed asphalt mixtures. It was noted that lower strain values of creep curves were obtained for the Tensile Creep Test (TCT) than for the Bending Beam Creep Test (BBCT), especially at lower temperatures. Results of thermal stress calculations indicated that higher reliability was obtained for the viscoelastic Monismith method based on the TCT results than for the simple quasi-elastic solution of Hills and Brien. The highest agreement with the TSRST results was also obtained for the Monismith method based on the TCT results. No clear relationships were noted between the predicted failure temperature and different methods of thermal stress calculations.

scholarly journals Cyclic Tension Test of AZ31 Magnesium Alloy at Elevated Temperature Realized in a Miniaturized Uniaxial Tensile Test Setup

2016 ◽  
Vol 854 ◽  
pp. 112-117
Author(s):  
Sebastian Suttner ◽  
Marion Merklein
Keyword(s):  
Elevated Temperature ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Elevated Temperatures ◽  
Kinematic Hardening ◽  
Cyclic Behavior ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Hardening Behavior ◽  
Aluminum And Magnesium Alloys

The use of new materials, e.g. aluminum and magnesium alloys, in the automotive and aviation sector is becoming increasingly important to reach the global aim of reduced emissions. Especially magnesium alloys with their low density offer great potential for lightweight design. However, magnesium alloys are almost exclusively formable at elevated temperatures. Therefore, material characterization methods need to be developed for determining the mechanical properties at elevated temperatures. In particular, cyclic tests at elevated temperatures are required to identify the isotropic-kinematic hardening behavior, which is important for numerically modeling the springback behavior. In this contribution, a characterization method for determining the cyclic behavior of the magnesium alloy AZ31B at an elevated temperature of 200 °C is presented. The setup consists of a miniaturized tensile specimen and stabilization plates to prevent buckling under compressive load. The temperature in the relevant area is introduced with the help of conductive heating. Moreover, the complex kinematic model according to Chaboche and Rousselier is identified, to map the transient hardening behavior of AZ31B after load reversal, which cannot be modeled with a single Bauschinger coefficient.

Deformation Behaviors of 6061 and 7075 Aluminum Tubes at Elevated Temperatures for Warm Hydroforming

2005 ◽  
Vol 475-479 ◽  
pp. 373-376
Author(s):  
Dong Woo Suh ◽  
Sung Man Sohn ◽  
Moon Yong Lee ◽  
Sang Yong Lee
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Local Necking ◽  
Aluminum Tubes ◽  
Hydroforming Process ◽  
Deformation Behaviors ◽  
Warm Hydroforming

The deformation behaviors of fully annealed or T6-treated 6061 and 7075 aluminum tubes are investigated at elevated temperature using uniaxial tensile test. Fully annealed 6061 and 7075 tube, and T6-treated 7075 tube do not show sharp local necking with an elongation of 50% at tensile temperature of 300oC, accordingly, it is expected that warm hydroforming process can be applied. The increase of tensile temperature does not significantly affect the total elongation of T6-treated 6061 tube.

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