Local Microstructure Control of Pure Aluminum Utilizing Fiber-Laser Aided Spot Heating System

2007 ◽  
Vol 558-559 ◽  
pp. 329-332 ◽  
Author(s):  
Toshiya Shibayanagi ◽  
Masahiro Tsukamoto ◽  
Nobuyuki Abe ◽  
Takamasa Matsumoto ◽  
Y. Soga
Keyword(s):  
Fiber Laser ◽  
Pure Aluminum ◽  
Heating System ◽  
Present System ◽  
Minimum Diameter ◽  
The Matrix ◽  
Cold Rolled ◽  
Aluminum Plates ◽  
Laser Heated ◽  
Similar Crystallographic Orientation

Spot heating system utilizing a fiber-laser has been developed in order to control recrystallization, grain growth process and texture development. The newly developed system enables the laser beam to be focused onto the surface of specimen with a minimum diameter of around 10 m. The maximum power of laser in the present system is 100W. Specimens of cold rolled pure aluminum plates of 1mm thick are used for local recrystallization treatment by the spot heating. After laser-spot heating, preferentially recrystallized grains appeared in the irradiated and heat affected region with a diameter depending on the laser power density. The present system enables spot heating on any critical points of the specimen surface. Some laser-heated specimen show locally recrystallized regions occupied by almost single grain having similar crystallographic orientation as that of cold rolled matrix. But the orientation of recrystallized grain is not always the same as that of the matrix. Selective spot heating on grains having peculiar orientation would bring about a possibility of texture control that has not been achieved by means of conventional materials processing.

Local Microstructure Control of Pure Aluminum Utilizing Fiber-Laser Aided Spot Heating System

2007 ◽  
pp. 329-332
Author(s):  
Toshiya Shibayanagi ◽  
Masahiro Tsukamoto ◽  
Nobuyuki Abe ◽  
Takamasa Matsumoto ◽  
Y. Soga
Keyword(s):  
Fiber Laser ◽  
Pure Aluminum ◽  
Heating System ◽  
Microstructure Control

scholarly journals Influence of Cold Rolled Deformation Degree and Heating Rates on Crystallite Dimension and Recrystallization Fraction of Aluminum Plates

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1428
Author(s):  
Yunlei Wang ◽  
Liping Ren ◽  
Jingren Dong ◽  
Chuanchuan Cao
Keyword(s):  
Pure Aluminum ◽  
Heating Rates ◽  
Initial State ◽  
Electron Backscattered Diffraction ◽  
Deformation Degree ◽  
High Deformation ◽  
Grain Boundary Characteristics ◽  
Crystallite Dimension ◽  
Cold Rolled ◽  
Aluminum Plates

In order to study the microstructure evolution rule of pure aluminum plates during different cold-rolled (CR) deformation degrees and annealing processes, samples with aCR deformation of 50~85%, heating rates of 60~100 °C/min and annealing at the target temperature of 350~500 °C were investigated. The microstructure, crystallite dimension and grain boundary characteristics were characterized by the methods of polarizing microscope (PM) and electron backscattered diffraction (EBSD). The results showed that the crystallite dimension of the initial state was 102 μm and ends up completely broken with an increase in the CR deformation degree. When the CR deformation increases to 85%, the deformed micro-bands were very small, with a band spacing of 5~10 μm. At this time, the grain distortion is more serious, there are more high-density grain defects, such as dislocations, and there is a high deformation of the storage energy, which is the energy preparation for the subsequent finished products to withstand the annealing process. The recrystallization fraction was higher with an increase in annealing temperature. After completed recrystallization, the grains showed an equiaxed shape. Orientation imaging and misorientation angle analysis showed that the red-oriented grains of the (001) plane, which had preferred nucleation, recrystallization and rapid grain growth. Final grains of the completed recrystallization are relatively coarse. Under the same deformation, the average crystallite dimension of the recrystallized grains decreases with an increase in annealing heating rate.

scholarly journals Energy and Exergy Analysis of a Plane Reflector Integrated Photovoltaic-Thermal Water Heating System

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Prem Sagar Naik ◽  
Arun Palatel
Keyword(s):  
Solar Radiation ◽  
Thermal Water ◽  
Winter Season ◽  
Performance Testing ◽  
Electrical Energy ◽  
Heating System ◽  
Present System ◽  
Exergetic Efficiency ◽  
Water Heating ◽  
Electrical Output

A photovoltaic-thermal water heating system is a hybrid energy conversion device transforming the incident solar radiation to yield electrical energy and thermal energy. Plane reflectors are found to be a convenient option for enhancing the solar radiation incident on the collector plane. The present work investigates the performance of a photovoltaic-thermal water heater integrated with a plane reflector mounted on the top edge of the collector for the tropical climate of Calicut (11.25°N, 75.78°E). Performance testing of the system has been carried out for the winter season of the location. The variations in thermal and electrical output are studied for various inclination angles of the reflector. The system performance is evaluated on the basis of system energy efficiency and exergetic efficiency. It is observed that there is a significant enhancement in the thermal and electrical output of the system with the integration of the reflector as compared to the system without the reflector. For the present system, the reflector tilt angle in the range of 85–100° has been found to be suitable in terms of enhanced system output and exergetic efficiency for the winter conditions of Calicut.

Process optimization for enhanced tribological properties of Al/MWCNT composites produced by powder metallurgy using artificial neural networks

2021 ◽  
Author(s):  
Turker Turkoglu ◽  
Sare Celik
Keyword(s):  
Powder Mixture ◽  
Pure Aluminum ◽  
Microstructural Analysis ◽  
Wear Test ◽  
Structural Defects ◽  
Wear Loss ◽  
Ann Model ◽  
Wear Properties ◽  
The Matrix ◽  
Artificial Neural

Abstract In order to eliminate the agglomeration problem of reinforcement in the nanocomposite, a two-step dispersion process was employed. Under ultra-sonication and ball milling, 1 wt.% of multi-walled carbon nanotubes (MWCNTs) were properly dispersed in pure aluminum (Al) (used as the matrix phase). The composite powder mixture was then consolidated in an inert Ar gas atmosphere by hot pressing under certain fabrication parameters. The powder mixture was characterized by Raman Spectroscopy, and it was found that MWCNTs did not cause structural defects in the pre-production process. The microstructural analysis of the sintered composites by scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDS), revealed that the reinforcement was uniformly distributed in the matrix. Wear test results indicated that the wear resistance of the composites increased with increase of MWCNT reinforcement, and the wear mechanism was determined to be a mixing type by examining the wear traces by SEM. In order to determine the effects of different process parameters on wear loss, a multilayer perceptron (MLP) based artificial neural network (ANN) was used, and experimental and predicted values were compared. It was noticed that the MLP based ANN model effectively evaluated the wear properties of the Al/MWCNT composites.

Investigation on the ballistic performance of rubber-aluminum (AA7075-T651) laminated plates reinforced with borosilicate glass balls

2021 ◽  
pp. 146442072110444
Author(s):  
Hasan Kasım
Keyword(s):  
Penetration Depth ◽  
Borosilicate Glass ◽  
Plate Thickness ◽  
High Strength ◽  
Laminated Plates ◽  
Front Face ◽  
Ballistic Performance ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
Aluminum Plates

In this study, the ballistic behavior of protective armor plates (PaP) obtained by curing between high structural strength AA7075-T651 aluminum plates by reinforcing with glass balls of two different rubber mixtures whose damping properties were developed with carbon nanotube and glass bubbles fillers were investigated. A total of six PaPs at 27, 30, and 35 mm heights were prepared using two different matrix damping rubbers. High-strength liner rubber used in air bellows is vulcanized on the front and back surfaces of PaPs. Between the PaPs, Ø15.875 and Ø6.747 mm, borosilicate glass balls were placed in a particular arrangement that coincides with the middle of the matrix rubber and does not have any gaps. Liner rubber cured on the front face has managed to hold the energy by forming a layer like clothing around the bullet cores. Glass balls between PAPs play an essential role in the energy absorption of GB-filled mixtures. In contrast, in MWCNT-filled mixtures, they act as a second damping element. The ballistic performance of PAPs prepared with multiwalled carbon nanotubes was determined to be better than those prepared with Glass Bubbles. Thanks to the superior mechanical properties and high aspect ratio of MWCNTs, the penetration and swelling heights of the matrix damping rubbers prepared to have excellent results compared to glass bubbles. With the increase in the thickness of the PaPs prepared with MWCNTs, the deformation effect of the penetration depth and bulging height created by the bullet on the anterior and posterior surfaces decreased. As the thickness of PaP increased from 27 mm to 35 mm, penetration depth decreased by 38%, and bulging height reduced by 35%. The amount of penetration and swelling increased in PaPs using rubber filled with glass bubbles. As the plate thickness increased, the damping feature decreased and the glass balls were activated, and the bullet was stopped.

Effects of Driving Force and Boundary Migration Velocity on Formation of Recrystallization Texture in Cold Rolled Pure Aluminum Sheets

2013 ◽  
Vol 753 ◽  
pp. 257-262 ◽  
Author(s):  
Wei Min Mao ◽  
Ping Yang
Keyword(s):  
Grain Growth ◽  
Driving Force ◽  
Recrystallization Texture ◽  
Pure Aluminum ◽  
Solute Drag ◽  
Texture Formation ◽  
Oriented Growth ◽  
Aluminum Sheets ◽  
Zener Drag ◽  
Cold Rolled

The effects of net driving force for migration of high angle grain boundaries were emphasized beside many other factors which could influence the process of texture formation during recrystallization annealing of 95% cold rolled pure aluminum sheets. The net driving force consists basically of stored energy. However, it could be reduced by recovery, boundary drag, solute drag and Zener drag in different extents, in which only boundary drag is mis-orientation dependent. It was indicated that both oriented nucleation and oriented growth have obvious influence on recrystallization texture, and how far they influence the texture depends also on the level of net driving force when the grain growth starts during annealing. Oriented growth, which is induced by the differences in boundary drag of differently oriented grains, and the corresponding texture formation, could be observed easily when the recrystallization proceeds under relative higher solute drag and Zener drag in commercial purity aluminum. The oriented nucleation process prevails during recrystallization of sufficiently recovered high purity aluminum with very low solute drag and Zener drag, after which strong cube texture forms. In this case the oriented growth indicates limited effect. Both the oriented growth and oriented nucleation will fail if high purity deformation matrix without clear solute drag and Zener drag has not experienced an obvious recovery before recrystallization grain growth, since extremely high net driving force leads to very small critical nucleus size and multiplicity of growing grains, which results in randomization of recrystallization texture.

Characteristics of Fiber Laser Lap Welding of Pure Aluminum Multi-thin Plate

2013 ◽  
Vol 30 (9) ◽  
pp. 931-942 ◽  
Author(s):  
Yun Seok Yang ◽  
Eun Kyeong Park ◽  
Ka Ram Lee ◽  
Young Tae Yoo
Keyword(s):  
Fiber Laser ◽  
Thin Plate ◽  
Pure Aluminum ◽  
Laser Lap Welding ◽  
Lap Welding

scholarly journals Transmission Kossel Study of the Structure of Cold-Rolled Iron and its Nucleation Behaviour

1977 ◽  
Vol 2 (3) ◽  
pp. 143-168 ◽  
Author(s):  
Y. Inokuti ◽  
R. D. Doherty
Keyword(s):  
Deformation Band ◽  
Boundary Migration ◽  
Rolling Plane ◽  
Deformation Bands ◽  
Thin Sections ◽  
Nucleation Mode ◽  
Grain Formation ◽  
The Matrix ◽  
Cold Rolled ◽  
The Difference

By examining thin sections and by use of the more strongly absorbed Ti Kα radiation rather than Fe Kα radiation it was found possible to obtain useful transmission Kossel patterns from iron that had been deformed 40% by rolling. Examination of the as–deformed material showed large misorientations in all the matrix grains (20–54°) and many of the grains showed deformation bands where the orientation changed rapidly (up to 15° over distances of 50 μm). On annealing the material recrystallized by strain-induced boundary migration with all the invaded grains being those with (111) parallel to the rolling plane. Only one example was found of new grain formation by mutual invasion across a deformation band, the main nucleation mode previously observed in aluminum deformed 40% by compression. The difference between the two examples appears to arise from the smaller misorientations of the deformation bands in rolled iron.

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