Deformation Behavior of Polycrystalline AZ31 Alloy at Room and Elevated Temperatures

2005 ◽  
Vol 488-489 ◽  
pp. 775-778
Author(s):  
Tsing Zhou ◽  
Goroh Itoh ◽  
Yohei Iseno ◽  
Yoshinobu Motohashi
Keyword(s):  
Deformation Behavior ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Az31 Alloy ◽  
Slip Systems ◽  
Type Specimens ◽  
Rolled Specimen ◽  
Hot Rolled

The hot-rolled and extruded AZ31 specimens are subjected to tensile tests at room and elevated temperatures. At room temperature, the yield stress of the hot-rolled specimen is significantly higher than that of the extruded, the reason for which is related to the different textures developed in the two type specimens, as well as the different slip systems activated. At elevated temperatures, the strain rate sensitivity and the activation energy are obtained to characterize the deformation mechanism of the alloy during the temperature range of 423~573K.

Room Temperature Ductility of B2-Type CoZr Intermetallic Compounds

2006 ◽  
Vol 980 ◽  
Author(s):  
Yasuyuki Kaneno ◽  
Takayuki Takasugi ◽  
Mitsuhiko Yoshida ◽  
Hiroshi Tsuda
Keyword(s):  
Room Temperature ◽  
Elevated Temperatures ◽  
Volume Fraction ◽  
Tensile Ductility ◽  
Tensile Tests ◽  
Ductile Deformation ◽  
Chemical Compositions ◽  
Second Phase ◽  
Intermetallic Alloys ◽  
Hot Rolled

AbstractB2 (CsCl) CoZr intermetallic alloys with different chemical compositions were hot-rolled and subsequently recrystallized to evaluate tensile properties and rolling workability. Co-49.0Zr, -49.5Zr and -50.0Zr alloys showed the B2-matrixed microstructure containing C15 Co2Zr dispersions, while Co-50.5Zr and -51.0Zr alloys showed the B2-matrixed microstructure containing C16 CoZr2 dispersions. These homogenized ingots were successfully hot-rolled without edge cracks, except for the Co-51.0Zr alloy. The tensile tests revealed that the Co-49.5Zr, -50.0Zr and -50.5Zr alloys exhibited a notable tensile ductility at room temperature as well as at elevated temperatures. Moreover, the recrystallized CoZr alloys were cold-rolled up to 70% reduction without intermediate annealing. It was also found that tensile ductility was most prominent in the Co-50.0Zr alloy with the least volume fraction of second phase dispersions in the investigated alloys, suggesting that the B2 phase of CoZr was inherently ductile. Deformation microstructures were characterized by means of XRD and TEM observations. Mechanisms responsible for the observed large tensile ductility of the CoZr alloys were discussed, on the basis of the observed deformation microstructures.

Plastic Deformation of Mo(Si,Al)2 Single Crystals with the C40 Structure

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi
Keyword(s):  
Single Crystals ◽  
Deformation Behavior ◽  
Basal Slip ◽  
Room Temperature ◽  
Slip Systems ◽  
Temperature Range ◽  
Al Content ◽  
Partial Dislocations ◽  
Increasing Temperature ◽  
Critical Resolved Shear Stress

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.

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.

Evolution of Microstructure during Hot Deformation of the PM Molybdenum Alloy TZM

2007 ◽  
Vol 539-543 ◽  
pp. 2725-2730 ◽  
Author(s):  
T. Mrotzek ◽  
Andreas Hoffmann ◽  
U. Martin ◽  
H. Oettel
Keyword(s):  
Yield Strength ◽  
Hot Deformation ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
High Strength ◽  
Tensile Tests ◽  
Primary Recrystallization ◽  
Molybdenum Alloy ◽  
Texture Formation ◽  
Evolution Of Microstructure

The molybdenum alloy TZM (Mo-0.5wt%Ti-0.08wt%Zr) is a commonly used structural material for high temperature applications. For these purposes a high strength at elevated temperatures and also a sufficient ductility at room temperature are being aimed. Preceding investigations revealed the existence of subgrains in hot deformed TZM. It was observed that with proceeding primary recrystallization and therefore with disappearance of subgrains the yield strength drops almost to a level of pure molybdenum. It is being assumed that the existence of a dislocation substructure has a pronounced effect on the yield strength of TZM. The aim of the present study was to evaluate the subgrain and texture formation and also to estimate the dislocation arrangement within subgrains during hot deformation. Hence, TZM rods were rolled to different degrees of deformation at a temperature above 0.5 Tm. The microstructure of the initial material was fully recrystallized. Texture formation, misorientation distributions and subgrain sizes were analyzed by electron backscattering diffraction (EBSD). Mechanical properties were characterized by tensile tests at room temperature and up to 1200°C. It was revealed, that with increasing degree of deformation a distinct substructure forms and therefore yield strength rises. Consequently, the misorientation between adjacent subgrains increases, their size decreases and a <110> fibre texture develops. To estimate the influence of texture on strength of TZM the Taylor factors are calculated from EBSD data.

Effect of High Temperature Caliber Rolling on Microstructure and Room Temperature Tensile Properties of Mg-3Al-1Zn (AZ31) Alloy

2013 ◽  
Vol 209 ◽  
pp. 6-9 ◽  
Author(s):  
Rajendra Doiphode ◽  
S.V.S. Narayana Murty ◽  
Nityanand Prabhu ◽  
Bhagwati Prasad Kashyap
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Yield Strength ◽  
Strain Rate ◽  
Tensile Properties ◽  
Room Temperature ◽  
Tensile Tests ◽  
Az31 Alloy ◽  
Rolling Temperature ◽  
Grain Sizes

Mg-3Al-1Zn (AZ31) alloy was caliber rolled at 250, 300, 350, 400 and 450 °C. The effects of caliber rolling temperature on the microstructure and tensile properties were investigated. The room temperature tensile tests were carried out to failure at a strain rate of 1 x 10-4s-1. The nature of stress-strain curves obtained was found to vary with the temperature employed in caliber rolling. The yield strength and tensile strength followed a sinusoidal behaviour with increasing caliber rolling temperature but no such trend was noted in ductility. These variations in tensile properties were explained by the varying grain sizes obtained as a function of caliber rolling temperature.

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.

Influence of Dislocation Mobility on Room and High Temperature Ductility of -Oriented Nial Single Crystals

1994 ◽  
Vol 364 ◽  
Author(s):  
M. A. Morris ◽  
J. P. Perez ◽  
R. Darolia
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
Room Temperature ◽  
Tensile Tests ◽  
Slip Systems ◽  
Dislocation Mobility ◽  
Screw Dislocations ◽  
Large Density ◽  
Thin Foils

AbstractThe dislocation configurations produced by room and high temperature compression of <100> oriented single crystals of binary NiAl and in those containing iron and hafnium additions have been analysed and compared to those obtained by hardness indentation and TEM insitu tensile tests. Kinking occurs during room temperature compression such that <100> dislocations are activated in all cases but the iron-containing alloy also exhibited a large density of <111> screw dislocations. The latter however, appear immobile when they are created by hardness indentations of thin foils, while only pile-ups of <100> segments can propagate. Similarly, although different slip systems are present after high temperature compression, only <100> dislocation segments have been confirmed to be mobile after room temperature hardness indentation of these predeformed thin foils. The improvement in ductility observed at room temperature in the predeformed specimens of the binary and the iron containing alloys has been attributed to the increased production of these mobile <100> dislocations.

Modeling of the Plastic Characteristics of AA6082 for the Friction Stir Welding Process

2015 ◽  
Vol 639 ◽  
pp. 309-316
Author(s):  
Sergio Pellegrino ◽  
Livan Fratini ◽  
Marion Merklein ◽  
Wolfgang Böhm ◽  
Hung Nguyen
Keyword(s):  
Friction Stir Welding ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Welding Process ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Welding Processes

Focus of this paper is to model the plastic forming behavior of AA6082, in order to develop the numerical FE analysis of the friction stir welding processes and the simulation of subsequent forming processes. During the friction stir welding process, the temperatures reached are until 500 °C and have a fundamental role for the correct performance of the process so the material data has to show a temperature dependency. Because of the tool rotation a strain rate sensitivity of the material has to be respected as well. In this context, the general material characteristics of AA6082 were first identified for different stress states. For the uniaxial state the standard PuD-Al used in the automotive industry was applied, for the shear state the ASTM B831-05 was used and for biaxial states the ISO 16842 was exploited. To characterize the plastic flow behavior of the AA6082 at elevated temperatures tensile tests were performed according to DIN EN ISO 6892-2 from 25 °C until 500 °C with a strain rate from 0.1 s-1up to 6.5 s-1.

Plastic Deformation of Ti3Al and Ti3Al/TiA1 Polycrystals

1988 ◽  
Vol 133 ◽  
Author(s):  
S. A. Court ◽  
J. P. A. Löfvander ◽  
M. A. Stucke ◽  
P. Kurath ◽  
H. L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Covalent Bonding ◽  
Relative Activity ◽  
Slip Systems ◽  
Dislocation Mobility ◽  
Two Phase ◽  
Influence Of Temperature ◽  
Transmission Electron

ABSTRACTSamples of polycrystalline Ti3Al-base alloys, and a two phase Ti3Al/TiAl mixture have been deformed at room temperature and at elevated temperatures and examined subsequently by transmission electron microscopy in order to determine the influence of temperature and alloy content on the relative activity of the various slip systems. In particular, the detailed influence of covalent bonding on dislocation mobility in Ti3Al has been identified.

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.

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