Microstructure and Mechanical Properties of Commercial Purity HIPed and Crushed Aluminum

2008 ◽  
Vol 584-586 ◽  
pp. 579-584 ◽  
Author(s):  
Quang Hien Bui ◽  
Guy F. Dirras ◽  
A. Hocini ◽  
Salah Ramtani ◽  
Akrum Abdul-Latif ◽  
...  

Ultrafine-grained aluminum microstructures were processed from commercial purity powder by combining hot isostatic pressing (HIP) and dynamic severe plastic deformation (DSPD). After the first step, the bulk consolidated material showed a random texture and homogeneous microstructure of equiaxed grains with an average size of 2µm. The material was then subsequently impacted, using a falling weight at a strain rate of 300s-1. The resulting material showed a microstructure having an average grain size of about 500 nm with a strong gradient of fiber-like crystallographic texture parallel to the impact direction. The mechanical properties of the impacted material were subsequently characterized under compressive tests at room temperature at a strain rate of 10-4s-1. The effect of the change of the deformation path on the mechanical response parallel (DN) and perpendicular (DT) to the impact direction was also investigated. These results are here discussed in relation with microstructure and texture evolution.

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 136 ◽  
Author(s):  
Dong ◽  
Zhang ◽  
Che ◽  
Yu ◽  
Meng ◽  
...  

The current work systematically investigated the microstructure, texture evolution, and mechanical properties of MDFed Mg-13Gd-4Y-2Zn-0.5Zr (wt%) alloy (GWZ) on the condition of high and low temperature cycle deformation. The high and low temperature cycle deformation was proposed on the basis of the conventional multi-directional forging (MDF) at decreasing temperature and annealing treatment. As a new method, it was aimed to timely uniform the microstructure and strengthen magnesium (Mg) matrix during the deformation process. A low accumulative strain of 3 after 1 pass resulted in a bimodal microstructure with undynamic recrystallized (unDRXed) regions and dynamic recrystallized (DRXed) grains, while a high accumulative strain of 12 after 4 passes lead to a homogeneous microstructure with fine DRXed grains. According to the experimental results, it indicated that the average grain size of 63 μm after homogenization treatment at 520 was refined remarkably to 5.20 μm after 4 passes at 420 °C through high and low temperature cycle deformation. The area fraction of DRXed grains was increased to 98.4%, which can be regarded as achieving complete DRX after 4 passes. The grain refinement was mainly caused by particle stimulation nucleation (PSN) and mechanism. As the MDF passes and accumulative strain increased, the basal texture was weakened and transformed from a strong basal texture to a random distribution gradually. Compared with conventional MDF at decreasing temperature, the mechanical properties were enhanced effectively. After 4 passes, the ultimate tensile strength (UTS), tensile yield strength (TYS), and failure elongation (FE) were 405 MPa, 305 MPa, and 13.1%, respectively.


2019 ◽  
Vol 38 (2019) ◽  
pp. 404-410 ◽  
Author(s):  
Weijuan Li ◽  
Haijian Xu ◽  
Xiaochun Sha ◽  
Jingsong Meng ◽  
Zhaodong Wang

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2105 ◽  
Author(s):  
Alon Ratner ◽  
Richard Beaumont ◽  
Iain Masters

Strain rate sensitivity has been widely recognized as a significant feature of the dynamic mechanical properties of lithium-ion cells, which are important for their accurate representation in automotive crash simulations. This research sought to improve the precision with which dynamic mechanical properties can be determined from drop tower impact testing through the use of a diaphragm to minimize transient shock loads and to constrain off-axis motion of the indenter, specialized impact absorbers to reduce noise, and observation of displacement with a high speed camera. Inert pouch cells showed strain rate sensitivity in an increased stiffness during impact tests that was consistent with the poromechanical interaction of the porous structure of the jellyroll with the liquid electrolyte. The impact behaviour of the inert pouch cells was similar to that of an Expanded Polypropylene foam (EPP), with the exception that the inert pouch cells did not show hysteretic recovery under the weight of the indenter. This suggests that the dynamic mechanical behaviour of the inert pouch cells is analogous to a highly damped foam.


Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 381-391
Author(s):  
Jan Herman ◽  
Marko Govednik ◽  
Sandeep P. Patil ◽  
Bernd Markert

In the present work, the mechanical properties of nanocrystalline body-centered cubic (BCC) iron with an average grain size of 10 Å were investigated using molecular dynamics (MD) simulations. The structure has one layer of crystal grains, which means such a model could represent a structure with directional crystallization. A series of uniaxial tensile tests with different strain rates and temperatures was performed until the full rupture of the model. Moreover, tensile tests of the models with a void at the center and shear tests were carried out. In the tensile test simulations, peak stress and average values of flow stress increase with strain rate. However, the strain rate does not affect the elasticity modulus. Due to the presence of void, stress concentrations in structure have been observed, which leads to dislocation pile-up and grain boundary slips at lower strains. Furthermore, the model with the void reaches lower values of peak stresses as well as stress overshoot compared to the no void model. The study results provide a better understanding of the mechanical response of nanocrystalline BCC iron under various loadings.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Fuan Wei ◽  
Jinhui Wang ◽  
Ping Li ◽  
Bo Shi

The mechanical properties of Mg-6Sn-3Al-1Zn alloy were enhanced with bimodal grain size disturbed in the microstructure uniformly; the Mg-6Sn-3Al-1Zn alloys were rolled with 60% thickness reduction at different rolling temperatures. The results have shown that the Mg-6Sn-3Al-1Zn alloys are composed of Mg2Sn phase and α-Mg matrix phase. When the rolling temperature was less than or equal to 400°C, with the rolling temperature increasing, the average size and volume fraction of Mg2Sn phase and the average grain size of small grains remained unchanged, the average grain size of large grains decreased, the volume fraction of small grains increased, and the yield strength of the alloy increased. When the rolling temperature reached 450°C, the average size and volume fraction of Mg2Sn phase and the average grain size of large grains increased, and the volume fraction of small grains and the yield strength of the alloy decreased. The elongation increased with the rolling temperature increasing, but the change trend of hardness was just opposite. When the alloy was rolled at 400°C, the average sizes of small grains, large grains, and Mg2Sn phases were 3.66 μm, 9.24 μm, and 19.5 μm, respectively. The volume fractions of small grains, large grains, and Mg2Sn phases were 18.6%, 77.6%, and 3.8%, respectively. And the tensile properties reached the optimum; for example, the tensile strength, yield strength, elongation, and Vickers hardness were 361 MPa, 289.5 MPa, 20.5%, and 76.3 HV, respectively.


2008 ◽  
Vol 23 (4) ◽  
pp. 904-910 ◽  
Author(s):  
T. El Kabir ◽  
A. Joulain ◽  
V. Gauthier ◽  
S. Dubois ◽  
J. Bonneville ◽  
...  

Metal-matrix composites are produced from Al powder and 30 vol% of icosahedral Al–Cu–Fe quasi-crystalline particles using a hot isostatic pressing technique. It is demonstrated that the initial icosahedral phase is transformed into the ω-Al70Cu20Fe10 tetragonal phase during the hot isostatic pressing (HIP) process. The mechanical properties of the composite were evaluated over the temperature range 293 to 773 K by performing compression tests at constant strain rate. The temperature dependence of the yield stress gives evidence of two temperature regimes with a transition temperature at approximately 423 K. Strain-rate sensitivity measurements support the change in rate-controlling deformation mechanisms at this temperature. It is proposed that cross-slip and/or climb mechanism control plastic flow. Finally, it is suggested that the phase transformation of the particle contributes positively to the improvement of the mechanical properties.


2019 ◽  
Vol 116 (6) ◽  
pp. 604 ◽  
Author(s):  
Lifeng Fan ◽  
Liying Jia ◽  
Rong Zhu ◽  
Jianzhong He

The grain-oriented silicon steel was produced by medium temperature reheating and two-stage cold rolling process, and the microstructure and texture of all metallurgical processes were studied. The results shown that the microstructure of the hot rolled strip was inhomogeneous in thickness direction, the surface layer was the recrystallized microstructures with average grain size of 42.29 µm, the center layer was fiber structure, and the Goss texture appeared at surface. The primary recrystallized microstructure with average grain size of 16 µm was obtained after decarburization annealing, which characterized by a strong γ-fiber texture and a weak Goss texture. The average size of inhibitors in hot rolled strip and decarburization annealed sheet were 9.078 and 21.691 nm respectively, they were mainly compound of nitride and sulfide with spherical or lump shapes. The coarse Goss grains with average size 17.57 mm were got after secondary recrystallization, and the magnetic induction B8 and iron loss P1.7/50 were 1.885 T and 1.10 W/Kg, respectively.


2013 ◽  
Vol 43 ◽  
pp. 70-84 ◽  
Author(s):  
Marko Knezevic ◽  
Rodney J. McCabe ◽  
Carlos N. Tomé ◽  
Ricardo A. Lebensohn ◽  
Shuh Rong Chen ◽  
...  

2011 ◽  
Vol 10 (1-2) ◽  
pp. 03 ◽  
Author(s):  
J. L. V. Coelho ◽  
J. M. L. Reis

In this work, the mechanical response of a composite material based on glass fibers embedded in an epoxy resin was experimentally studied as a function of strain rate and temperature. It was shown that for the temperature range from 23 to 100 °C the elastic properties of the composite are significant affected and the strain rate influences only the ultimate strength. The experimental research data and the approaches presented in this work should significantly extend our knowledge of the effect of elevated temperatures on the mechanical behavior of high temperature polymer matrix composites.


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