A Study of the Kinetic of Precipitation and the Morphology of Precipitates Induced by Plastic Deformation in Al-Zn Alloys

1982 ◽  
Vol 21 ◽  
Author(s):  
C. Mai ◽  
P. Merle ◽  
J. Merlin ◽  
F. Livet
Keyword(s):  
Plastic Deformation ◽  
Tensile Strength ◽  
Small Angle ◽  
Room Temperature ◽  
Volume Fraction ◽  
Tensile Axis ◽  
Precipitate Volume Fraction ◽  
Ellipsoidal Shape ◽  
Flat Shape ◽  
Zn Alloys

ABSTRACTThe influence of plastic deformation on the kinetic of precipitation and the morphology of precipitates in an Al-Zn 4.4 % at. studied by T.E.P. and SAXS is reported. Some results can be pointed out ; after a given amount plastic deformation at room temperature by tensile strength:i - the precipitates have a flat shape (instead of the spherical or ellipsoidal shape usualy observed in this alloys.ii - the precipitate volume fraction is a function of strain (ε) and strain rate (ė). For a given ė, the higher precipitate volume fraction is obtained with the higher ε. For a given ε, the lower ė the higher the volume fraction of precipitates.iii - the scattering intensities at small angle for three orientations of the sample (α =0,45°, 90° where α is the angle between the axis of tensile and the scattering vector- are different. A calculation for an anisotropic orientation of flat discs shows that precipitates have a preferential texture. The orientation is about 50° from the tensile axis.

Influence of Isothermal Forging Temperature on Microstructure and Tensile Properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb-0.4Si-1.5Ta Near-α Titanium Alloy

2010 ◽  
Vol 97-101 ◽  
pp. 153-157
Author(s):  
Tao Wang ◽  
Hong Zhen Guo ◽  
Jian Hua Zhang ◽  
Ze Kun Yao
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Tensile Properties ◽  
Room Temperature ◽  
Volume Fraction ◽  
Constant Strain Rate ◽  
Isothermal Forging ◽  
Α Phase ◽  
Transus Temperature

The microstructures and room temperature and 600°C tensile properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb -0.4Si-1.5Ta alloy after isothermal forging have been studied. The forging temperature range was from 850°C to 1075°C, and the constant strain rate of 8×10-3/S-1 was adopted. With the increase of forging temperature, the volume fraction of primary α phase decreased and the lamellar α phase became thicker when the temperatures were in range of 850°C -1040°C; The grain size became uneven and the α phase had different forms when the forging temperature was 1040°C and 1075°C respectively; The tensile strength was not sensitive to the temperature and the most difference was within 20MPa. Tensile strength and yield strength attained to the maximum when temperature was 1020°C; the ductility decreased with the increase of forging temperature, and this trend became more obvious if forging temperature was above the β-transus temperature.

Fabrication and investigation on the properties of ilmenite (FeTiO3)-based Al composite by accumulative roll bonding

2019 ◽  
Vol 54 (10) ◽  
pp. 1259-1271 ◽  
Author(s):  
Medhat Elwan ◽  
A Fathy ◽  
A Wagih ◽  
A R S Essa ◽  
A Abu-Oqail ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Accumulative Roll Bonding ◽  
Room Temperature ◽  
Volume Fraction ◽  
Raw Material ◽  
Accumulative Roll Bonding Process ◽  
Roll Bonding ◽  
Hardness Tests ◽  
Al Composite

In the present study, the aluminum (Al) 1050–FeTiO3 composite was fabricated through accumulative roll bonding process, and the resultant mechanical properties were evaluated at different deformation cycles at ambient temperature. The effect of the addition of FeTiO3 particle on the microstructural evolution and mechanical properties of the composite during accumulative roll bonding was investigated. The Al–2, 4, and 8 vol.% FeTiO3 composites were produced by accumulative roll bonding at room temperature. The results showed improvement in the dispersions of the particles with the increase in the number of the rolling cycles. In order to study the mechanical properties, tensile and hardness tests were applied. It was observed that hardness and tensile strength improve with increasing accumulative roll bonding cycles. The microhardness and tensile strength of the final composites are significantly improved as compared to those of original raw material Al 1050 and increase with increasing volume fraction of FeTiO3, reaching a maximum of ∼75 HV and ∼169 MPa for Al–8 vol.% FeTiO3 at seventh cycle, respectively.

Tensile Strength and Impact Toughness of Gallium-Bearing Near-α Titanium Alloys

2014 ◽  
Vol 783-786 ◽  
pp. 619-623 ◽  
Author(s):  
Tomonrori Kitashima ◽  
K.S. Suresh ◽  
Y. Yamabe-Mitarai ◽  
S. Iwasaki
Keyword(s):  
Tensile Strength ◽  
Impact Toughness ◽  
Titanium Alloys ◽  
Room Temperature ◽  
Volume Fraction ◽  
Charpy Impact ◽  
Minor Effect ◽  
Future Design ◽  
Aspect Ratios ◽  
A Minor

The present study aims to quantify the properties of Ga-bearing near-titanium alloys in order to aid the future design of new compositions with Ga addition. The effect of different amounts of Sn and Ga, with an almost constant value in the Al equivalent without the formation of 2 phase, on microstructure, tensile strength and Charpy impact toughness was investigated at room temperature and 650°C. The microstructures after forging, hot rolling and heat treatment showed a bimodal structure. Increasing Ga decreased the 0.2% proof stress at 650°C. However, these alloys showed similar impact value at room temperature which was about 40 J/cm2. Increasing the amount of Ga increased the volume fraction of the equiaxed phase. The amount of Ga had only a minor effect on grain size, misorientation angles and grain aspect ratios of the alloy. However, Ga addition had a strong influence on the evolution of texture. Formation of <10-10> and <10-11> || normal direction (ND) fibers were observed in the Ga added samples, in addition to <0001> || ND fiber with a weak <10-11> || ND fiber. The Ga-free sample contained a strong <0001> || ND fiber. Other fibers were not observed.

Optimization of the Product of Strength and Plasticity of Hot-Stamped WHT1300HF High Strength Steel

2013 ◽  
Vol 798-799 ◽  
pp. 280-285
Author(s):  
Kai Liu ◽  
Bo Chi ◽  
Zeng Min Shi ◽  
Ji Bin Liu ◽  
Li Jian
Keyword(s):  
Tensile Strength ◽  
High Strength Steel ◽  
Retained Austenite ◽  
Room Temperature ◽  
Volume Fraction ◽  
High Strength ◽  
Carbide Precipitation ◽  
Maximum Value ◽  
Untransformed Austenite ◽  
Strength And Plasticity

The quenching and partitioning (Q&P) process was performed on high strength steel WHT1300HF at 250-350 °C for 30 to 90 s, respectively, for the improvement of its product of strength and plasticity (PSP). ε-carbide precipitation was observed in all the specimens partitioned at each temperature for different periods of time due to inadequate amount of Si in the composition of WHT1300HF steel. The volume fraction of retained austenite at room temperature in the partitioned specimens is extremely low due to the lack of carbon enrichment in untransformed austenite at the partitioning temperature as a result of the carbide precipitation. The decrease of tensile strength and increase of elongation are caused by the partitioning treatment, a maximum value of the PSP (17.6 GPa%) is achieved by partitioning at 300 °C for 60 s.

Microstructural characterization and mechanical behavior of Cr25Ni35NbM alloy dissimilar weld joint for application in a hydrogen reformer furnace

2020 ◽  
Vol 117 (6) ◽  
pp. 612
Author(s):  
Jingfeng Guo ◽  
Wenwen Liu ◽  
Chunxiu Li ◽  
Xiaoming Zhang
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Weld Joint ◽  
Room Temperature ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Dissimilar Weld ◽  
Weld Joints

The microstructural characterization and mechanical behavior of Cr25Ni35NbM/15CrMo and Cr25Ni35NbM/SUS321 dissimilar weld joints were studied in this paper. The microstructure, room temperature and high temperature (1173 K) tensile strength of dissimilar weld joints were analyzed through optical microscopy (OM), scanning electron microscopy (SEM) and electronic universal tensile testing machine. The microstructure of HAZ in 15CrMo steel of Cr25Ni35NbM/15CrMo dissimilar weld joint transformed from ferrite-pearlite into ferrite-martensite. A large volume fraction of α phase was found to have precipitated in the HAZ of SUS321 austenitic stainless steel for Cr25Ni35NbM/SUS321 dissimilar weld joint. At room temperature, the tensile strength and yield strength of these two type dissimilar weld joints is less than Cr25Ni35NbM alloy similar weld joint. The high temperature tensile strength of these two type dissimilar weld joints is less than Cr25Ni35NbM alloy similar weld joint. Both at room and high temperature, the fracture locations of two types dissimilar weld joints are the HAZ of the base metal 15CrMo and SUS321 stainless steel, respectively. It indicates that the weak part of the Cr25Ni35NbM alloy dissimilar weld joints is the low-performance base metals 15CrMo and SUS321 stainless steel.

Tensile and Creep Rupture Properties of Co + Co3AIC0.5 Two-Phase Alloys

1998 ◽  
Vol 552 ◽  
Author(s):  
R. Ishibashi ◽  
S. Nakamura ◽  
Y. Aono ◽  
S. Miura ◽  
Y. Mishima
Keyword(s):  
Tensile Strength ◽  
Volume Fraction ◽  
Tensile Axis ◽  
Rupture Life ◽  
Creep Rupture ◽  
Average Particle ◽  
Phase Volume ◽  
Two Phase ◽  
Phase Volume Fraction ◽  
Rupture Properties

ABSTRACTIt is expected that the κ-phase of the intermetallic compound Co3A1C0.5 would strengthen Cobase alloys used at high temperatures like the γ' -phase of Ni-base superalloys. Tensile and creep rupture properties of Co+κ two-phase alloys with κ-phase volume fractions up to 0.75 were investigated. Alloy samples made by directional solidification casting were annealed at 1573 K for 3.6 ks and at 1373 K for 28.8 ks in vacuum, followed by Ar gas cooling. Tensile tests at RT and 1073 K and creep rupture tests at 1089 K under a stress of 172 MPa were conducted with the tensile axis parallel to the solidification direction. In alloys with low κ-phase volume fraction, cuboidal K-precipitates with average particle diameters of 0.4 to 1.0 μm were observed. They were coherent with the Co(fcc) matrix with misfits of about 3%. As the κ-phase volume fraction increased, tensile strength also increased. The alloy with κ-phase volume fraction of 0.4 had a 0.2% proof stress of 817MPa, tensile strength of 1047 MPa at RT, creep rupture life of 1.43 Ms, and tensile strain higher than 10%. These strengths are better than those of the conventional Co-base alloys. However, ductility of alloys with κ-phase volume fraction larger than 0.4 decreased due to large eutectic and primary κ-phase particles.

Effect of Volume Fraction of Reinforcement on the Microstructure and Mechanical Properties of In Situ (TiB+TiC)/Ti Composite

2011 ◽  
Vol 335-336 ◽  
pp. 137-141 ◽  
Author(s):  
Yuong Chen ◽  
Chang Jiang Zhang ◽  
Fan Tao Kong ◽  
Hong Zhi Niu ◽  
Fang Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Room Temperature ◽  
Volume Fraction ◽  
Microstructural Analysis ◽  
Matrix Composites ◽  
Alloy Matrix

In the present study, Ti-6Al-2.5Sn-4Zr-0.7Mo-0.3Si-0.3Y alloy matrix composites reinforced with TiB and TiC were fabricated by combustion-assisted cast utilizing the reaction between titanium and B4C, graphite. The microstructure, room temperature mechanical properties were presented and discussed. Microstructural analysis of the composites revealed that the prior β grain size as well as the thickness of α colony significantly refined with increasing of volume fraction. At room temperature (RT), tensile strength and elastic modulus increase significantly, while the ductility drops gradually possibly because of the cracking of TiB whiskers and TiC particles.

Microstructure and Mechanical Properties of Al2O3-TiC/Al in Situ Composites

2006 ◽  
Vol 326-328 ◽  
pp. 1857-1860
Author(s):  
Hong Mei Chen ◽  
Hua Shun Yu ◽  
Jing Zhang ◽  
Lin Zhang ◽  
Guang Hui Min
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Room Temperature ◽  
Volume Fraction ◽  
Matrix Alloy ◽  
Co2 Gas ◽  
In Situ Composites ◽  
In Situ Reaction ◽  
The Matrix

The Al2O3-TiC/Al composites were prepared by injecting CO2 gas into Ti contained Al-Si alloy melts. The microstructure of the composites was examined by XRD, SEM and TEM. It was indicated that both Al2O3 and TiC particles can be formed by the in situ reaction of CO2 with Ti and Al in the melten alloys. The Al2O3 and TiC particles in size of 0.3~1.5μm distributed uniformly in the matrix. The volume fraction of the particles is mainly depend upon the time of CO2 injection.The tensile strength at room temperature of the composites can reach 346.08MPa and the hardness is 149.6MPa HBS, repectively, which are higher than those of the matrix alloy.

Grain Refinement for Strengthening in Fe3Al-based Alloys Through Thermomechanical Processing

2008 ◽  
Vol 1128 ◽  
Author(s):  
Satoru Kobayashi ◽  
Akira Takei ◽  
Takayuki Takasugi
Keyword(s):  
Tensile Strength ◽  
Grain Refinement ◽  
Room Temperature ◽  
Volume Fraction ◽  
Thermomechanical Processing ◽  
Tensile Ductility ◽  
Thermomechanical Process ◽  
Fine Grained ◽  
The Matrix ◽  
Matrix Orientation

AbstractA thermomechanical process (TMP) for grain refinement was performed in bulk Fe3Al-based alloys containing ˜10% volume fraction of κ-Fe3AlC precipitates. In the TMP, κ particles play an important role in reducing the inhomogeneity of recrystallization due to the matrix orientation. The grain size was refined to ˜20 μm by optimizing the κ particle size. A fine-grained and pancake/recovered microstructure fabricated by the TMP showed more than 1200 MPa tensile strength and 8% tensile ductility at room temperature in air. The tensile strength of this material was higher than those of conventional wrought Fe3Al alloys at temperatures between room temperature and 500 °C, and the specific tensile strength was as high as that of the Ti-6Al-4V alloy at temperatures above 400 °C.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

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