47 research outputs found
Application of Bayesian Neural Networks to Predict Strength and Grain Size of Hot Strip Low Carbon Steels
Texture evolution and plastic anisotropy of commercial purity titanium/SiC composite processed by accumulative roll bonding and subsequent annealing
The final publication is available at Elsevier via https://doi.org/10.1016/j.matchemphys.2018.08.027. © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/In this study, commercial purity titanium (CPTi) with SiC particle reinforcements produced using accumulative roll bonding (ARB) process and subsequent annealing. Texture evolution and plastic anisotropy in different steps of the process were studied. ARBed material exhibited a significant magnitude of anisotropy of mechanical properties. Moreover, a strong TD split basal texture with basal poles tilted 25° away from the normal direction toward the transverse direction was developed in the ARBed samples. Higher normal anisotropy obtained for ARB–annealed sheet, compared to that of the starting titanium sheet, indicated lower susceptibility to thinning. However, ARB–annealed sheet exhibited higher planar anisotropy ( = 0.048 for ARB–annealed sheet and  = –0.434 for starting titanium). Higher resistance to thinning of the ARB–annealed sheets compared to the starting titanium was ascribed to the higher uniform elongation shown by annealed sheets. Furthermore, it was concluded that finer grain size of ARB–annealed sheet resulted in higher work hardening of the sheet, which in turn, increased the uniform elongation of ARB–annealed sample
Mode â… fracture analysis of aluminum-copper bimetal composite using finite element method
The properties of Al–Cu bimetallic composite are investigated employing the finite element method to understand the nature of the composite materials under different loading conditions. In this regard, Al and Cu metallic sheets were implemented to analyze cold-roll bonding (CRB) and to monitor the bonding conditions. After rolling the materials were investigated for their stress distribution and bonding as well as fracture behavior. Finite element investigation was used by the ANSYS software to analyze the stress-strain distribution in the metal layers. The results indicate that the appropriate joining of Al–Al and Al–Cu can be achieved using the CRB process. The stress distribution based on the Von-Mises criterion was calculated and validated by simulation studies. For crack simulations, on the other hand, the results showed that during crack propagation, the materials showed different behaviors owing to the varying properties of Al and Cu. Also, for both the tests, stress distribution in 2D and 3D were simulated, and different stress criteria were obtained and compared. Moreover, optical and scanning electron microscopies were used to study the characteristics of the materials and to support FEM outputs
Complementary research on the Al–Cu nanostructured composite processed by ARB: finite element, crystal plasticity, intermetallic, and failure analysis
A unique Al–Cu composite was manufactured using the accumulative roll bonding (ARB) process. For characterization purposes, a variety of methods was conducted on the resulting composite. Also, the shear band formation which is a prevalent phenomenon in the ARBed materials was analyzed using the finite element method (FEM). For experimental analysis, the crystallographic texture was evaluated for the material by the X-ray diffraction method (XRD). A well-developed rolling (β-fiber) texture was dominated on the Al side, however, recrystallization led to the occurrence of other component mainly around orientation on the Cu side. Upon annealing, the formation of different intermetallic compounds (IMCs) was observed and evaluated using scanning electron microscopy (SEM). An unexpected AlCu4 was detected between the layers as the prominent IMC after the annealing process. Furthermore, the shear punch test was employed for the material's mechanical characterization. It was observed that the strength of the composite material was higher than that of primary metals i.e., Al and Cu. Finally, failure analysis revealed a ductile fracture with separated layers at earlier cycles and a brittle fracture at higher ARB cycles
On the texture evolution of aluminum-based composites manufactured by ARB process: a review
Texture development in materials processed by the accumulative roll bonding (ARB) is vastly investigated using a variety of experimental methods in recent years. Thus, a summary of the most recent studies is reviewed and is the subject of this paper. There are important variables affecting the texture during the rolling process including alloying element, multilayered, adding particles, the direction of rolling (strain paths), and recrystallization. For each one of the mentioned factors, the main results were simply summarized and then compared with each other using statistical evaluations. The focus of the present study, therefore, is to escalate our understanding of the mechanisms involved in determining the texture of Al-based materials produced by the ARB process
Homogenizing optimization, microstructure and tensile properties evolution of CuCrFeNi2Mn0.5 alloy
In this research, a central composite design of experiment has been carried out to investigate the homogenizing treatment of the low-cost CuCrFeNi2Mn0.5 alloy. For this purpose, the alloy was cast via the vacuum induction melting method and homogenized under different time/temperature conditions, according to experimental design. Finally, a model was developed using Response Surface Methodology (RSM), determining the relationship between homogenizing parameters and segregation ratio values. According to the results obtained from the model, the best homogenization conditions yielding optimal segregation ratio (SRÂ =Â 1) was heat treating at 1100OC for 17Â h. Microstructural studies showed that the mentioned alloy maintained its phase stability after homogenization and had a single FCC phase solid solution. In addition, due to the necessity of quenching the high entropy alloy samples after long-time homogenization at high temperatures, it was shown that an effective factor contributing to the loss of mechanical properties of the homogenized sample is the tensile residual stresses on the surface upon quenching
Synthesis of the AlCrCuMnNi high entropy alloy through mechanical alloying and spark plasma sintering and investigation of its wear behavior
In this research, AlCrCuMnNi high entropy alloy (HEA) was produced through mechanical alloying (MA) process and then was subjected to spark plasma sintering (SPS) process at different temperatures. The structural and microstructural properties of the alloy were examined after each process. The sample SPSed at 900 °C was then subjected to wear test at room temperature (RT) and 400 °C. The results of MA process were consistent with the thermodynamic analysis results as they revealed the formation a dual-phase HEA after 90 h of milling, which consisted of face-centered cubic and body-centered cubic phases. Increasing SPS temperature led to an increase in the hardness and density of the alloy due to the higher quality of sintering and formation of intermetallic compounds. Additionally, it was seen that the wear resistance of the AlCrCuMnNi HEA is higher at 400 °C compared to RT due to the formation of a hard oxide film on the sliding surface and reduction of the friction coefficient. Moreover, the wear mechanisms of the AlCrCuMnNi HEA at RT were delamination and adhesion which changed to abrasive wear and delamination at elevated temperatures
Grain and texture evolution in nano/ultrafine-grained bimetallic Al/Ni composite during accumulative roll bonding
The evolution of grain structure during plastic deformation has a significant effect on texture variations and, in turn, the material properties. However, the metal physics leading to a stationary grain size regime in rolled Al combined with a harder phase remains poorly understood. Therefore, the grain and texture evolution in the Al phase and the possible grain coarsening mechanisms operating during accumulative roll bonding (ARB) were investigated in this work. Three ARB cycles were performed at room temperature with the aim of obtaining a bimetallic Al-Ni composite. The microstructure and texture evolutions in this composite were characterized via field emission gun scanning electron microscopy combined with electron backscatter diffraction. With increasing strain, the lamellar grain structure of Al developed into a semi-equiaxed grain structure. Correspondingly, the grain length and thickness decreased from 672 to 0.84 A mu m and 24.8 to 0.60 A mu m, respectively. Grain fragmentation was, however, most efficient in the initial stages of rolling, since continuous dynamic recrystallization prevented further grain refinement especially in the last cycle. Consequently, after a strain of 2.7, the refinement continued at decreasing rates, yielding a fragmentation ratio of one at a lower strain than that reported for single-phase Al composites. The mid-section layers of the Al phase were characterized by a mixture of shear and plane strain compression textures. After the third ARB cycle, the Al phase was characterized by a near random texture resulting from grain fragmentation. This fragmentation was induced by local plastic flow in the Al phase, owing to the presence of hard Ni fragments
Effects of Process Control Agent Amount, Milling Time, and Annealing Heat Treatment on the Microstructure of AlCrCuFeNi High-Entropy Alloy Synthesized through Mechanical Alloying
This study was conducted to investigate the characteristics of the AlCrCuFeNi high-entropy alloy (HEA) synthesized through mechanical alloying (MA). In addition, effects of Process Control Agent (PCA) amount and milling time were investigated using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The results indicated that the synthesized AlCrCuFeNi alloy is a dual phase (FCC + BCC) HEA and the formation of the phases is strongly affected by the PCA amount. A high amount of PCA postponed the alloying process and prevented solid solution formation. Furthermore, with an increase in the PCA amount, lattice strain decreased, crystallite size increased, and the morphology of the mechanically alloyed particles changed from spherical to a plate-like shape. Additionally, investigation of thermal properties and annealing behavior at different temperatures revealed no phase transformation up to 400 °C; however, the amount of the phases changed. By increasing the temperature to 600 °C, a sigma phase (σ) and a B2-ordered solid solution formed; moreover, at 800 °C, the FCC phase decomposed into two different FCC phases