Springback Behavior of an Invar Sheet and Its Perforated Form

2006 ◽  
Vol 505-507 ◽  
pp. 781-786
Author(s):  
Yi Che Lee ◽  
Fuh Kuo Chen
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Test Results ◽  
Bending Tests ◽  
Predicted Values ◽  
Springback Behavior ◽  
Good Agreement

The springback behavior of an invar sheet and its perforated form were examined in the present study. The mechanical properties for invar sheet and perforated invar-sheet at elevated temperatures were first obtained from tensile tests. The test results suggest that both invar sheet and perforated invar-sheet have favorable formability at temperature higher than 200oC. An analytical model was also established to predict the springback of the invar sheet and its perforated form under bending conditions at various elevated temperatures. In order to verify the predicted results, the V-bending tests were conducted for the invar sheet at various temperatures ranging from room temperature to 300. The experimental data indicate that the springback decreases with the rise in temperature for both invar sheet and perforated invar-sheet. The good agreement between the experimental data and the predicted values confirms the validity of the proposed theoretical model as well.

Effect of Ca and Sr Content on Elevated Temperatures Mechanical Properties of a Cast AZ91 Magnesium Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 141-144
Author(s):  
Ippei Takeuchi ◽  
Kinji Hirai ◽  
Yorinobu Takigawa ◽  
Tokuteru Uesugi ◽  
Kenji Higashi
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Creep Resistance ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Az91 Magnesium Alloy ◽  
Additional Amount ◽  
Az91 Magnesium ◽  
Second Phases

The effect of Ca and Sr content on the microstructure and mechanical properties of a cast AZ91 magnesium alloy is investigated. Ca and Sr additions in AZ91 magnesium alloy are expected high creep resistance. The microstructure of the alloy exhibits the dendritic α-matrix and the second-phases forming networks on the grain boundary. Tensile tests at elevated temperatures between 448 and 523K reveal that the creep resistance was improved with increasing the additional amount of Ca, especially more than 1.0wt%. From the perspective of grain refinement effect, it is expected that the additions of Ca and Sr to AZ91 magnesium alloy not only improve creep resistance but also improve mechanical properties at room temperature.

scholarly journals On the Impact of the Intermetallic Fe2Nb Laves Phase on the Mechanical Properties of Fe-6 Al-1.25 Nb-X W/ Mo Fully Ferritic Light-Weight Steels

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1693
Author(s):  
Robin Emmrich ◽  
Ulrich Krupp
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Xrd Analysis ◽  
Tensile Tests ◽  
Laves Phase ◽  
Particle Analysis ◽  
Strength Increase ◽  
Niobium Content ◽  
The Impact

The present study aims at the development of precipitation hardening fully ferritic steels with increased aluminum and niobium content for application at elevated temperatures. The first and second material batch were alloyed with tungsten or molybdenum, respectively. To analyze the influence of these elements on the thermally induced precipitation of the intermetallic Fe2Nb Laves phase and thus on the mechanical properties, aging treatments with varying temperature and holding time are performed followed by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) including elemental contrast based particle analysis as well as hardness measurements and tensile tests at room temperature and at 500 °C. The incorporation of molybdenum into the Laves phase sets in at an earlier stage of aging than the incorporation of tungsten, which leads to faster growth and coarsening of the Laves phase in the molybdenum-alloyed steel. Nevertheless, both concepts show a fast and massive increase in hardness (280 HV10) due to precipitation of Laves phase during aging at 650 °C. After 4 h aging, the yield strength increase at room temperature is 100 MPa, which stays stable at operation temperatures up to 500 °C.

Influence of Annealing Treatment on Formability and Springback for Magnesium Alloy Sheets

2010 ◽  
Vol 443 ◽  
pp. 189-194 ◽  
Author(s):  
Dae Yong Kim ◽  
Bum Kyu Hwang ◽  
Young Seon Lee ◽  
Sang Woo Kim ◽  
Young Hoon Moon
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Annealing Treatment ◽  
Tensile Tests ◽  
Strip Casting ◽  
Bending Tests ◽  
Magnesium Alloy Az31 ◽  
Twin Roll ◽  
Springback Angle

The purpose of this work is to experimentally investigate the effect of annealing treatment on the formability and springback at room temperature for magnesium alloy AZ31 sheets, which were produced by rolling through reversible warm mill after twin roll strip casting. Microstructure evolutions were investigated using OM after annealing at temperature raging from 350°C to 450°C. Tensile tests at room temperature were performed to show the influence of annealing treatment on mechanical properties. In order to evaluate the formability in stamping processes, the Erichsen cupping tests were carried out and the Erichsen number were measured. As for springback, the V shaped air bending tests were achieved and the angle changes after springback were collected. The experimental results showed that Erichsen numbers increased by the annealing treatment, while springback angle decreased.

The Mechanical Properties of Fe-36.5Al and its Cr or ti Containing Alloys at Elevated Temperature

1994 ◽  
Vol 364 ◽  
Author(s):  
Dingqiang Li ◽  
Yi Liu ◽  
Aidang Shan ◽  
Dongliang Lin
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Ternary Alloys ◽  
Transgranular Cleavage ◽  
Feal Alloy ◽  
Fracture Surfaces ◽  
Increasing Temperature

AbstractThe mechanical properties of B2 structural FeAl alloys, prepared by hot rolling, at elevated temperatures have been measured by tensile tests. The alloys of Fe-36.5at.%A1, Fe-36.5at.%A1-5at.%Cr and Fe-36.5at.%Al-2at.%Ti were taken for tensile tests at a temperature range from room temperature to 1000°C. The fracture surfaces of these alloys were observed by SEM. The results showed that elongations of these alloys increased with increasing temperature when the testing temperatures were above 600°C. All the maximum elongations of these alloys appeared at 1000°C and those of Fe-36.5A1, Fe-36.5Al-5Cr, and Fe-36.5Al-2Ti alloys were 120%, 183% and 208% respectively. Fracture surfaces showed that failure of these alloys was by a combination of intergranular fracture and transgranular cleavage below 700°C. but showed a ductile fracture above 700°C. The ductility and strength of ternary alloys were higher than that of binary FeAl alloy at elevated temperatures, especially at high temperature. The <111> dislocations and helices have been observed in Fe-36.5A1 alloy by TEM. The large elongation of FeAl alloy at high temperature resulted from <111> dislocations slipping and <111> helices climbing.

Electron transport properties of InP

1980 ◽  
Vol 58 (7) ◽  
pp. 923-930 ◽  
Author(s):  
H. J. Lee ◽  
J. Basinski ◽  
L. Y. Juravel ◽  
J. C. Woolley
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Thermoelectric Power ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Scattering Parameters ◽  
Electron Transport Properties ◽  
Predicted Values ◽  
Experimental Values ◽  
Good Agreement

Measurements of electrical conductivity σ and Hall coefficient RH have been made as a function of temperature in the range room temperature to 250 °C and as a function of magnetic field up to 3.2 T on single crystal n-type samples of InP with carrier concentrations in the range 3.5 × 1021 to 1.2 × 1024 m−3. Theoretical calculations of σ and RH have been made using the method of Fletcher and Butcher and the resulting values fitted to the experimental data by using various scattering parameters as adjustable. The parameters so obtained have then been used to predict further magnetoresistance values and values of thermoelectric power and Nernst–Ettingshausen coefficient. The predicted values of magnetoresistance and thermoelectric power show good agreement with experimental values but not those of the Nernst–Ettingshausen coefficient, possibly due to experimental problems.

A research on the effect of retrogression and re-aging heat treatment on hot tensile properties of AA7075 aluminum alloys

2021 ◽  
pp. 1-23
Author(s):  
Talha Sunar ◽  
Dursun Ozyurek
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Ductile Fracture ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Xrd Analysis ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Tensile Behaviour ◽  
Heat Treated

Abstract Aluminium alloys are preferred in most industries due to the functional properties they provide. It is known that alloys that can be processed with heat treatments shows better mechanical properties. 7xxx series alloys can be processed vi heat treatments and are often used in environmental conditions such as extreme temperatures and corrosive environments. Corrosive sensitivities such as stress corrosion cracking (SCC) can be observed with the effect of working conditions. It is known that retrogression and re-aging (RRA) heat treatment provide corrosion resistance and decrease the SCC velocity. The purpose of this study is to examine the tensile behaviour of annealed and retrogression-re-aging (RRA) heat treated AA7075 alloys at elevated temperatures. The mechanical properties of the alloys were investigated by conducting tensile tests at room temperature (RT), 100, 200, and 300°C. Hardness tests were performed at room temperature on the samples which were taken from tensile test specimens after tensile tests. The potential effects of test temperature on mechanical and microstructural properties were examined. The annealed and RRA heat treated alloys were characterized by scanning electron microscope (SEM), and X-ray diffraction (XRD) analysis. As a result, an increase in strength and hardness of the RRA treated AA7075 alloys was observed. Ductility of the RRA alloy was lower compared to the annealed AA7075 alloy. Fracture surface examinations showed that there was a semi-ductile fracture below 200°C and ductile fracture at temperatures of 200 and 300°C. Ductility was observed to increase with increasing temperature.

Notched Strength Prediction and Verification of APC-2 Composite Laminates at Elevated Temperature

2009 ◽  
Vol 79-82 ◽  
pp. 1563-1566 ◽  
Author(s):  
Ming Hwa R. Jen ◽  
Yi Chun Sung ◽  
Yu Chung Tseng
Keyword(s):  
Experimental Data ◽  
Elevated Temperature ◽  
Composite Laminates ◽  
Elevated Temperatures ◽  
Characteristic Length ◽  
Tensile Tests ◽  
Stress Criterion ◽  
Static Tensile ◽  
Notched Strength ◽  
Good Agreement

The notched strength of AS-4/PEEK (APC-2) composite laminates with a central hole at elevated temperature was systematically studied by both analytical and empirical methods. First, the APC-2 cross-ply [0/90]4s panels were fabricated and cut into samples. Each sample was drilled a hole in the center with five kinds of diameters, such as d=0(unnotched), 1, 2, 3, and 4mm. Then, the samples were subjected to quasi-static tensile tests at elevated temperatures, including 25°C (RT), 75, 100, 125, 150 and 175°C, to measure their mechanical properties. The average values of received notched strength were affected significantly by stress concentration and high temperature. In analysis the prediction of residual strength by point stress criterion (PSC) was adopted first and found unsatisfactory due to at least 15% errors with experimental data. Then, the modified PSC was used with the varied characteristic length dependent on nature of material and specimen geometry. The predicted notched strengths by the modified PSC model were in very good agreement with experimental data. The predictive results were not only precisely validated, but extended to the application at elevated temperature.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

Mechanical Behavior of Ti-6Al-4V Manufactured by Electron Beam Additive Fabrication

2013 ◽  
Author(s):  
Leila Ladani ◽  
Lalit Roy
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Lead Time ◽  
Aerospace Industry ◽  
Tensile Tests ◽  
Test Results ◽  
Great Resistance ◽  
Additive Fabrication ◽  
Anisotropy Effect ◽  
The Cost

Additive Layer Fabrication, in particular Electron Beam Additive Fabrication (EBAF), has recently drawn much attention for its special usability to fabricate intricately designed parts as a whole. It not only increases the production rate which reduces the production lead time but also reduces the cost by minimizing the amount of waste material to a great extent. Ti6Al4V is the most common type of material that is currently being fabricated using EBAF technique. This material has been used in aerospace industry for several reasons such as excellent mechanical properties, low density, great resistance to corrosion, and non-magnetism. The effects of build direction of layers (namely, addition of layers along one of the x, y & z directions with respect to the build table) and the anisotropy effect caused by it has not been explored vigorously. This anisotropy effect has been investigated in this work. Different mechanical properties such as Yield Strength (YS), Ultimate Tensile Strength (UTS), and Modulus of Elasticity (E) of these three types of Ti6Al4V are determined using tensile tests and are compared with literature. The tensile test results show that YS and UTS for flat-build samples have distinguishably higher values than those of the side-build and top-build samples.

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