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Effect of heat treatment on the precipitation in Al–1 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys

Research Abstract
The fine-scale precipitates, that occurs during aging, the supersaturated Al–1.0 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys have been investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The strength of the alloys increases as a high density of very fine β″ coherent and β′ semicoherent precipitates nucleate. The precipitates compositions have been determined by analyzing the X-ray diffraction (XRD) charts, by using Scherrer equation. The obtained results showed that the β″ and β′ precipitates size lies in the nanometer range (from 5 nm to 32 nm). In addition, increasing Si concentration has exhibited an increase in the density of the precipitates, which fortifies the physical properties.
Research Authors
A. Gaber, N. Afify, M.S. Mostafa, Gh. Abbady
Research Department
Research Journal
Alloys and Compounds
Research Member
Research Pages
PP. 295–300
Research Rank
1
Research Vol
Vol. 477, No. 1-2
Research Year
2009

Effect of heat treatment on the precipitation in Al–1 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys

Research Abstract
The fine-scale precipitates, that occurs during aging, the supersaturated Al–1.0 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys have been investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The strength of the alloys increases as a high density of very fine β″ coherent and β′ semicoherent precipitates nucleate. The precipitates compositions have been determined by analyzing the X-ray diffraction (XRD) charts, by using Scherrer equation. The obtained results showed that the β″ and β′ precipitates size lies in the nanometer range (from 5 nm to 32 nm). In addition, increasing Si concentration has exhibited an increase in the density of the precipitates, which fortifies the physical properties.
Research Authors
A. Gaber, N. Afify, M.S. Mostafa, Gh. Abbady
Research Journal
Alloys and Compounds
Research Pages
PP. 295–300
Research Rank
1
Research Vol
Vol. 477, No. 1-2
Research Year
2009

Effect of heat treatment on the precipitation in Al–1 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys

Research Abstract
The fine-scale precipitates, that occurs during aging, the supersaturated Al–1.0 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys have been investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The strength of the alloys increases as a high density of very fine β″ coherent and β′ semicoherent precipitates nucleate. The precipitates compositions have been determined by analyzing the X-ray diffraction (XRD) charts, by using Scherrer equation. The obtained results showed that the β″ and β′ precipitates size lies in the nanometer range (from 5 nm to 32 nm). In addition, increasing Si concentration has exhibited an increase in the density of the precipitates, which fortifies the physical properties.
Research Authors
A. Gaber, N. Afify, M.S. Mostafa, Gh. Abbady
Research Department
Research Journal
Alloys and Compounds
Research Member
Research Pages
PP. 295–300
Research Rank
1
Research Vol
Vol. 477, No. 1-2
Research Year
2009

Effect of heat treatment on the precipitation in Al–1 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys

Research Abstract
The fine-scale precipitates, that occurs during aging, the supersaturated Al–1.0 at.% Mg–x at.% Si (x = 0.6, 1.0 and 1.6) alloys have been investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The strength of the alloys increases as a high density of very fine β″ coherent and β′ semicoherent precipitates nucleate. The precipitates compositions have been determined by analyzing the X-ray diffraction (XRD) charts, by using Scherrer equation. The obtained results showed that the β″ and β′ precipitates size lies in the nanometer range (from 5 nm to 32 nm). In addition, increasing Si concentration has exhibited an increase in the density of the precipitates, which fortifies the physical properties.
Research Authors
A. Gaber, N. Afify, M.S. Mostafa, Gh. Abbady
Research Department
Research Journal
Alloys and Compounds
Research Member
Abdel-fatah Jaber Mohamoud Abd Allah Elbos
Research Pages
PP. 295–300
Research Rank
1
Research Vol
Vol. 477, No. 1-2
Research Year
2009

Radial and spiral distortion of magnetic lenses with fields of the form B(z)zn

Research Abstract
Both radial and spiral distortion of magnetic lens with the field distribution in the form B(z)αzn are analyzed by means of Scherzer's formula. To estimate the performance of the image in electron microscope the dimensionless quality factors (F.Z. Marai, T. Mulvey, Sherzer's formula and the correction of spiral distortion in the electron microscope, Ultramicroscopy 2 (1977) 187–192.), for both radial and spiral distortion is calculated. The results have been compared with different projector lenses.
Research Authors
A.S.A. Alamir
Research Department
Research Journal
Optik
Research Pages
PP. 984–986
Research Rank
1
Research Vol
Vol. 120. No. 18
Research Year
2009

Filling of very deep, wide trenches by BenzoCycloButene polymer

Research Abstract
A process for deep trench filling by BenzoCycloButene (BCB) polymer is explored. Deep trenches with 100-μm depth and different aspect ratios from 1.4 to 20 have been successfully filled by BCB. Besides, chemical mechanical polishing (CMP) of BCB is studied with the main goals of smoothing surface topography of substrate after BCB filling and removing excess BCB coating which may be necessary in some applications. Removal rate for BCB, V RR, of about 0.24 μm/min has been achieved for hard cured BCB films using acid slurry. After CMP, the BCB layer showed a roughness of about 1.36 nm (Rq, measured by atomic force microscopy, AFM).
Research Authors
Hicham Mahfoz Kotb, K. Isoird, F. Morancho, L. Théolier, T. Do Conto
Research Department
Research Journal
Microsyst Technol
Research Pages
PP. 1395–1400
Research Publisher
Springer Berlin / Heidelberg
Research Rank
1
Research Vol
Vol. 15. No. 1
Research Year
2009

A New Junction Termination Using a Deep Trench Filled With BenzoCycloButene

Research Abstract
Numerous techniques have been used to improve the voltage handling capability of high voltage power devices with the aim to obtain the breakdown of a plane junction. In this work, a new concept of low cost, low surface and high efficiency junction termination for power devices is presented and experimentally validated. This termination is based on a large and deep trench filled by BCB (BenzoCycloButene) associated to a field plate. Simulation results show the important impact of trench design and field plate width on termination performances. The experimental breakdown voltage of this Deep Trench Termination (DT2) is close to 1300 Volts: this value validates not only the concept of the DT2 but also the choice of the BCB as a good dielectric material for this termination.
Research Authors
L. Théolier, H. Mahfoz-Kotb, K. Isoird, F. Morancho, S. Assié-Souleille, and N. Mauran
Research Department
Research Journal
IEEE Electron Device Letters
Research Pages
PP. 687-689
Research Rank
1
Research Vol
Vol. 30, No. 6
Research Year
2009

Various heating rates (VHR) as a method for crystallization kinetics determination and its application to Se75.5Te20Sb4.5 chalcogenide glass

Research Abstract
A new method (VHR method) has been derived from Johnson-Mehl-Avrami (JMA) transformation rate equation to calculate the crystallization kinetic parameters of a glassy system. These parameters include the activation energy of crystallization E (kJ/mol), the kinetic exponent n and the frequency factor Ko (s-1). The VHR method starts with obtaining E. Let us consider xi(t) as the volume fractions of crystallization which are obtained at various heating rates βi (K/min). The method for obtaining E depends on finding the temperatures Ti (K) and the times ti (s) which are required to produce the same values of xi(t) at various values of βi. Next, the value of n is obtained by using the temperatures T1 (K) and T2 (K) and the times t1 (s) and t2 (s) which are extracted at two different values of the volume fraction x1(t) and x2(t) at the same heating rate. Finally, the value of Ko may be obtained at any value of x(t) after obtaining the values of E and n, successively. The applicability and the full descriptions of the VHR method have been thoroughly tested on computer simulated crystallization curves. Also,the validity ofthe VHR method has been checked in the cases of n being temperature-independent and temperature-dependent parameter. The VHR technique has been used to estimate the crystallization parameters of Se75.5Te20Sb4.5 chalcogenide glass under non-isothermal conditions.
Research Authors
M.S. Rasheedya, A.S. Soltana, A.A.I. Abd-Elmageed
Research Department
Research Journal
Alloys and Compounds
Research Pages
pp. 581-586
Research Publisher
Elsevier, Lausanne, SUISSE (1991) (Revue)
Research Rank
1
Research Vol
Vol. 472, No. 1-2
Research Year
2009

Various heating rates (VHR) as a method for crystallization kinetics determination and its application to Se75.5Te20Sb4.5 chalcogenide glass

Research Abstract
A new method (VHR method) has been derived from Johnson-Mehl-Avrami (JMA) transformation rate equation to calculate the crystallization kinetic parameters of a glassy system. These parameters include the activation energy of crystallization E (kJ/mol), the kinetic exponent n and the frequency factor Ko (s-1). The VHR method starts with obtaining E. Let us consider xi(t) as the volume fractions of crystallization which are obtained at various heating rates βi (K/min). The method for obtaining E depends on finding the temperatures Ti (K) and the times ti (s) which are required to produce the same values of xi(t) at various values of βi. Next, the value of n is obtained by using the temperatures T1 (K) and T2 (K) and the times t1 (s) and t2 (s) which are extracted at two different values of the volume fraction x1(t) and x2(t) at the same heating rate. Finally, the value of Ko may be obtained at any value of x(t) after obtaining the values of E and n, successively. The applicability and the full descriptions of the VHR method have been thoroughly tested on computer simulated crystallization curves. Also,the validity ofthe VHR method has been checked in the cases of n being temperature-independent and temperature-dependent parameter. The VHR technique has been used to estimate the crystallization parameters of Se75.5Te20Sb4.5 chalcogenide glass under non-isothermal conditions.
Research Authors
M.S. Rasheedya, A.S. Soltana, A.A.I. Abd-Elmageed
Research Department
Research Journal
Alloys and Compounds
Research Member
Research Pages
pp. 581-586
Research Publisher
Elsevier, Lausanne, SUISSE (1991) (Revue)
Research Rank
1
Research Vol
Vol. 472, No. 1-2
Research Year
2009

Factorial experimental design applied to DRIE for optimized process in power electronics applications requiring high-aspect ratio trenches

Research Abstract
A reliable factorial experimental design was applied to DRIE for specifically producing high-aspect ratio trenches. These trenches are to be used in power electronics applications such as active devices: deep trench superjunction MOSFET (DT-SJMOSFET) and passive devices: 3D integrated capacitors. Analytical expressions of the silicon etch rate, the verticality of the profiles, the selectivity of the mask and the critical loss dimension were extracted versus the process parameters. The influence of oxygen in the passivation plasma step was observed and explained. Finally, the analytical expressions were applied to the devices objectives. A perfectly vertical trench 100-μm deep was obtained for DT-SJMOSFET. Optimum conditions for reaching high-aspect ratio structures were determined in the case of high-density 3D capacitors.
Research Authors
Magali Brunet, Pascal Dubreuil, Hicham Mahfoz-Kotb, Aline Gouantes, Anne-Marie Dorthe
Research Department
Research Journal
Microsystem Technologies
Research Pages
pp. 1449-1457
Research Publisher
Springer Berlin / Heidelberg
Research Rank
1
Research Vol
Vol. 15, No. 9
Research Year
2009
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