Mechanical Properties of E21 Ti3AlC-base Alloy

2006 ◽  
Vol 980 ◽  
Author(s):  
Hideki Hosoda ◽  
Tomonari Inamura ◽  
Kenji Wakashima
Keyword(s):  
Mechanical Properties ◽  
Base Alloy ◽  
The Body ◽  
Nominal Composition ◽  
Second Phase ◽  
Positive Temperature ◽  
Compression Tests ◽  
Octahedral Interstitial Site ◽  
Temperature Range ◽  
Average Grain Size

AbstractMechanical properties and phase constitution of an E21-type Ti3AlC-base alloy were investigated by compression tests in a temperature range from room temperature (RT) to 1273K, scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The unit cell of E21 Ti3AlC is constructed by ¡§L12 Ti3Al¡¨ and a carbon atom occupying the body-center octahedral-interstitial-site surrounded by the Ti atoms. The nominal composition of the alloy was chosen to be the stoichiometric composition of 60mol%Ti-20mol%Al-20mol%C. The alloy was synthesized by mechanical alloying using high purity elemental powders followed by hot pressing at 1473K for 3hrs. It was found by XRD and SEM that the alloy was mainly composed of E21 Ti3AlC in addition to Cr2AlC-type Ti2AlC precipitates as a second phase. The density of Ti3AlC is calculated to be 4.29g/cm3 based on the lattice parameter of 0.4134nm of E21. The average grain size was 2μm by SEM. By the compression tests, the 0.2% flow stress at the temperature range from RT to 1073K exceeded 1GPa. The yield stress is comparably higher than those of other E21 intermetallic carbides: at 1073K, 1084MPa for Ti3AlC, 50MPa for Mn3AlC and 135MPa for Fe3AlC. Besides, a weak positive temperature dependence of strength was observed where the peak temperature was around 900K. This suggests that a Kear-Wilsdorf type dislocation pinning mechanism may be activated. It is concluded that E21 Ti3AlC-base alloy shows promise for a new high-temperature light-weight structural material.

Mechanical Properties of L12 Type Zn3Ti-Base Alloy

1998 ◽  
Vol 552 ◽  
Author(s):  
Hideki Hosoda ◽  
Shuji Hanada
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Ball Mill ◽  
Room Temperature ◽  
Base Alloy ◽  
Positive Temperature ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tests

ABSTRACTAn alloy composed of L12-type Zn3Ti was investigated in terms of phase stability and mechanical properties. Zn and Ti powders were mixed at a composition of Zn-25mol%Ti using a ball mill in Ar, and an ingot was made by melting the powders. Optical microscopy, X-ray diffraction analysis and thermogravimetry - differential thermal analysis were carried out. Mechanical properties were investigated by Vickers hardness tests at room temperature (RT) and compression tests from RT to 703K in Ar. It is found that (1) the alloy is mainly composed of L12 Zn3Ti, (2) the alloy has weak positive temperature dependence of strength, and (3) normalized strength by melting point is comparable to that of L12 Al3Ti-Cr alloys. L12 Zn3Ti has HV178 and is brittle at RT. Reaction temperatures of Zn-rich portion of the Zn-Ti phase diagram were also reinvestigated and a peritectic-reaction temperature between Zn3Ti and liquid + Zn2Ti is determined to be at 880K.

Critical Strain for the Initiation of Dynamic Recrystallization in a Ni-Fe Base Alloy

2004 ◽  
Vol 449-452 ◽  
pp. 577-580
Author(s):  
Young Sang Na ◽  
Young Mok Rhyim ◽  
J.Y. Lee ◽  
Jae Ho Lee
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Critical Strain ◽  
Base Alloy ◽  
Strain Rate Range ◽  
Boundary Phase ◽  
Alloy 718 ◽  
Compression Tests ◽  
Temperature Range ◽  
Critical Strains

In order to quantitatively analyze the critical strain for the initiation of dynamic recrystallization in Ni-Fe-based Alloy 718, a series of uniaxial compression tests was conducted in the temperature range 927°C - 1066°C and the strain rate range 5 x 10-4s-1- 5 s-1with varying initial grain size. The critical strains were graphically determined based on one parameter approach and microscopically confirmed. The effect of γ'' (matrix-hardening phase) and δ (grain boundary phase)on the critical strain was simply discussed. The constitutive model for the critical strain of Alloy 718 was constructed using the experimental data obtained from the higher strain rate and the temperature range between 940°C and 1040°C.

Variation of Microstructure and Mechanical Properties of ZW61 Magnesium Alloy Solidified under Different Pressures

2022 ◽  
Vol 327 ◽  
pp. 3-10
Author(s):  
Shu Sen Wu ◽  
Xiao Gang Fang ◽  
Shu Lin Lü ◽  
Long Fei Liu ◽  
Wei Guo
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Volume Fraction ◽  
Applied Pressure ◽  
Second Phase ◽  
Cast State ◽  
Microstructure And Properties ◽  
Microstructure Refinement ◽  
Porosity Reduction ◽  
Average Grain Size

There is little datum related to microstructure and properties of Mg alloys squeeze-casted with pressure over 200 MPa. In this study, the microstructure and properties of Mg-6Zn-1.4Y (ZW61) alloy solidified under 100MPa to 800MPa were investigated. The results show that a remarkable microstructure refinement and porosity reduction can be reached through solidification under high pressure. The average grain size and the volume fraction of second phase, i.e. quasicrystal I-phase, decrease continuously with the increase of applied pressure. The tensile properties, especially elongation, are obvious enhanced because of the microstructure refinement and castings densification under high pressure. The ultimate tensile strength and elongation of ZW61 alloy in as-cast state are 243 MPa and 18.7% when the applied pressure is 800 MPa, which are increased by 35% and 118% respectively, compared with that of the gravity castings.

Mechanical Properties of E21 (Mn, Fe)3AIC-Base Alloys

1998 ◽  
Vol 552 ◽  
Author(s):  
Kensyo Suzuki ◽  
Hideki Hosoda ◽  
Shuji Hanada
Keyword(s):  
Mechanical Properties ◽  
Flow Stress ◽  
Temperature Dependence ◽  
Volume Fraction ◽  
Primary Phase ◽  
Positive Temperature ◽  
Compression Tests ◽  
Positive Temperature Dependence ◽  
Fe Content ◽  
Work Hardening Coefficient

ABSTRACTMechanical properties of E21 (Mn, Fe)3AlC-base alloys were investigated. The E21 crystal structure is closely related to L12, and thereby E21 compounds are expected to exhibit superior properties similar to those of the L12 Ni3AL. Nominal compositions are fixed to be 60mol%(Mn, Fe)-20mol%A1–20mol%C. Alloys were prepared by mechanical alloying and hot pressing. ICP chemical analysis, X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis were carried out for alloy characterization. Mechanical properties were evaluated by Vickers hardness tests at room temperature (RT) and compression tests from RT to 1273K. Strain rate dip tests were also carried out. It is found that most alloys are composed of two phases of E21 as the primary phase and graphite as the precipitates, and that the volume fraction of graphite increases with increasing Fe content. Hardness and 0.2% flow stress at RT are raised with increasing Fe content. At RT, 0.2% flow stress and fracture strength of Fe3A1C alloy used are 2.9GPa and 3.4GPa, respectively. An alloy containing 40%Mn-20%Fe shows weak positive temperature dependence of strength at 700–800K, similar to the observation in some Co3AIC alloys. Moreover, work-hardening coefficient of all alloys shows strong positive temperature dependence below 700K. These results suggest the occurrence of K-W related mechanism for plastic deformation in these alloys.

Mechanical Properties of Bulk Nanocrystalline Silver-Using Compression Tests

2010 ◽  
Vol 152-153 ◽  
pp. 1313-1316
Author(s):  
Guo Jun Hu ◽  
Zhi Quan Hong
Keyword(s):  
Mechanical Properties ◽  
Coarse Grained ◽  
Strain Rates ◽  
Test Results ◽  
Compression Tests ◽  
Static Test ◽  
Rate Dependent ◽  
Average Grain Size ◽  
Bulk Nanocrystalline ◽  
The Relationship

In this paper, the compression test on the bulk nanocrystalline sliver ( n Ag) with average grain size of 50 nm was made. The stress-strain curves under different strain rates were obtained by test. The test results show that the mechanical behavior of n Ag is rate-dependent, and the dynamic compress yield stress are about 1.5 times of that n Ag in static test condition; The effect of strain harding on n Ag is smaller than that of coarse-grained silver (c Ag) in plastic deformation; The relationship between the yield strength and the logarithm of strain rate is approximately linear.

The Constitutive Relationship and Processing Map of Hot Deformation in A100 steel

2016 ◽  
Vol 35 (4) ◽  
pp. 399-405 ◽  
Author(s):  
Yongkang Liu ◽  
Zongmei Yin ◽  
Junting Luo ◽  
Zhang Chunxiang ◽  
Yanshu Zhang
Keyword(s):  
Strain Rate ◽  
Type Equation ◽  
Strain Rate Range ◽  
Constitutive Relationship ◽  
Compression Tests ◽  
Rate Range ◽  
Temperature Range ◽  
Average Grain Size ◽  
Strain Data ◽  
Different Strains

AbstractIsothermal compression tests were conducted on A100 steel using a Gleeble 1500 thermal simulator at a temperature range of 900–1,200°C and strain rate range of 0.001–3 s−1. Results show that the A100 steel has higher strength than the Aermet 100 steel at high temperatures. Constant values, such as A, α, and n, and activate energy Q were obtained through the regression processing of the stress–strain data curves under different strains. A set of constitutive equations for A100 steel was proposed by using an Arrhenius-type equation. The optimum processing craft ranges for A100 steel based on the analysis of the hot working diagram and deformation mechanism are as follows: temperature range of 1,000–1,100°C and strain rate range of 0.01–0.1 s−1. The average grain size within this working range is 7–22.5 μm.

Effect of Cr content on microstructure and mechanical properties of annealed large-dimensional bulk nanocrystalline Fe–Al–Cr alloys by self-propagating combustion synthesis

2019 ◽  
Vol 9 (6) ◽  
pp. 641-647
Author(s):  
Hongding Wang ◽  
Qiangqiang Wang ◽  
Hong Liu ◽  
Peiqing La ◽  
Zhengning Li
Keyword(s):  
Mechanical Properties ◽  
Combustion Synthesis ◽  
Deformation Behavior ◽  
Isothermal Treatment ◽  
Second Phase ◽  
Cr Content ◽  
Microstructure Transformation ◽  
Average Grain Size ◽  
Bulk Nanocrystalline ◽  
20 Nm

Large-dimensional bulk nanocrystalline Fe–Al–Cr alloys with different chromium contents (5, 10, 15 and 20 wt.%) were prepared by self-propagating combustion synthesis. After isothermal treatment at 1000 °C for 16 hours, the microstructure transformation and the deformation behavior of Fe–Al–Cr alloys were studied and discussed. After annealing, the nanocrystalline matrix of the alloys changed slightly, and the average grain size remained as approximately 20 nm. Owing to the changes in the distribution and shape of the second phase, the annealed nanocrystalline Fe–Al–Cr alloys with different chromium contents provided good plasticity and strength. The annealed Fe–Al–Cr alloy with 15 wt.% chromium achieved the best comprehensive mechanical properties.

Mechanical properties and dislocation dynamics of GaP

1989 ◽  
Vol 4 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Ichiro Yonenaga ◽  
Koji Sumino
Keyword(s):  
Mechanical Properties ◽  
Dislocation Dynamics ◽  
Dynamic State ◽  
Strain Rates ◽  
Compression Tests ◽  
Stress Strain ◽  
Temperature Range ◽  
Strain Behavior ◽  
Defect Complexes ◽  
Impurity Defect

Mechanical properties of GaP crystals are investigated in the temperature range 600–900 °C by means of compression tests. Stress-strain characteristics of a GaP crystal in the temperature range 600–800 °C are very similar to those of a GaAs crystal in the temperature range 450–600 °C. The dynamic state of dislocations during deformation is determined by means of the strain-rate cycling technique. The deformation of GaP is found to be controlled by the dislocation processes the same as those in other kinds of semiconductors such as Si, Ge, and GaAs. The velocity v of dislocations that control deformation is deduced to be v = v0 τ exp(–2.2 eV/kT) as a function of the stress τ and the temperature T, where v0 is a constant and k the Boltzmann constant. The Portevin-LeChatelier effect is observed in the stress-strain behavior in the deformation at high temperatures and under low strain rates, which may be attributed to the locking of dislocations by impurities or impurity-defect complexes.

Mechanical properties of GaAs crystals

1987 ◽  
Vol 2 (2) ◽  
pp. 252-261 ◽  
Author(s):  
Ichiro Yonenaga ◽  
Utako Onose ◽  
Koji Sumino
Keyword(s):  
Mechanical Properties ◽  
Surface Condition ◽  
Gaas Crystal ◽  
Compression Tests ◽  
Czochralski Technique ◽  
Lower Yield ◽  
Temperature Range ◽  
Defect Complexes ◽  
Transmission Electron ◽  
Effective Generation

Mechanical properties of GaAs crystals grown by the liquid encapsulated Czochralski technique and the boat technique are investigated by means of compression tests. Stressstrain characteristics of a GaAs crystal in the temperature range 400°–500°C are very similar to those of a Si crystal in the temperature range 800°–900°C. This seems to reflect the fact that the dislocation mobility in a GaAs crystal in the former temperature range is comparable to that in a Si crystal in the latter temperature range. Dislocations in GaAs crystals are found to be easily immobilized at an intermediate temperature due to gettering of impurities and/or impurity-point defect complexes. In comparison to a Si crystal, the surface of a GaAs crystal seems to involve irregularities that act easily as effective generation centers for dislocations. Thus the magnitude of the yield stress of an aged GaAs crystal is controlled by the surface condition and is not influenced by the density of dislocations involved in the crystal. The socalled steady state of deformation is realized in a GaAs crystal in the deformation stage after the lower yield point as in Si and Ge crystals. Dislocation distributions in a deformed GaAs crystal observed by transmission electron microscopy is very similar to those in deformed Si and Ge crystals.

scholarly journals Influence of casting temperature on microstructures and mechanical properties of Cu50Zr45.5Ti2.5Y2 metallic glass prepared using copper mold casting

2009 ◽  
Vol 24 (10) ◽  
pp. 3108-3115 ◽  
Author(s):  
Zhengwang Zhu ◽  
Haifeng Zhang ◽  
Hao Wang ◽  
Bingzhe Ding ◽  
Zhuang-Qi Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metallic Glass ◽  
Shear Bands ◽  
Great Influence ◽  
Casting Temperature ◽  
Second Phase ◽  
Compression Tests ◽  
Metallic Glass Matrix Composite ◽  
Microstructures And Mechanical Properties ◽  
Rapidly Solidified

The influence of casting temperatures on microstructures and mechanical properties of rapidly solidified Cu50Zr45.5Ti2.5Y2 alloy was investigated. With increasing casting temperatures, the amount of the crystalline phase decreases. At a high casting temperature, i.e., 1723 K, glass-forming ability (GFA) of the present alloy is enhanced. The results imply that adjusting the casting temperature could be used for designing the microstructures of bulk metallic glass matrix composite. Nanoindentation tests indicated that CuZr phases are slightly softer and can accommodate more plastic deformation than the amorphous matrix. Compression tests confirmed that this kind of second phase (CuZr) precipitated under lower casting temperatures helps to initiate multiple shear bands, resulting in a great improvement in mechanical properties of the samples. Our work indicates that casting temperatures have a great influence on GFA, microstructures, and mechanical properties of the rapidly solidified alloy, therefore controlling the casting temperature is crucial to the production of BMGs.

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