Search results

Defect Investigation of Plastically Deformed Al 5454 Wrought Alloy Using PADBS and Electrical Measurements M.
Abdel-Rahman Physics Department, Faculty of Science, El-Minia University, Egypt * e-mail : el_rahman@yahoo.com, ** e-mail : emadbadawi@yahoo.com Keywords: Positron annihilation Doppler broadening spectroscopy; electrical measurements; Al 5454 alloy; defect concentration; dislocation density Abstract Positron Annihilation Doppler Broadening Spectroscopy (PADPS) is a nondestructive technique used in materials science.
The chemical composition of Al 5454 alloy is shown in Table (1).
Table 1 The chemical composition of Al 5454 wrought alloy Element Cr Cu Ti Zn Si Fe Mn Mg Al Al 5454 0.05- 0.2 0.1 o.2 0.25 0.25 0.4 0.5-1 2.4-3 Balance Al 5454 Alloy has a very good resistance to atmospheric corrosion, very good weldability and good formability by pressing, drawing and roll-forming.
A sandwich configuration has been used to guide the positron into the Al 5454 samples.

Table 1 Chemical composition of three types of HNS /wt% C Cr Mn Mo Si P Al Ni O N Fe HNS-77 0.057 19.15 18.83 2.25 0.38 ≤0.03 <0.03 — 0.0052 0.77 Bal.
The results of YS, UTS and El present the same regularity in HNS-77 and HNS-96 except HNS-110.
The plots of YS, UTS and El decrease monotonously in aged HNS-110 as shown in Fig. 6 (c).
Katada et al., ISIJ Int., Vol. 42 (2002), p. 1391
Jiang et al., Adv.

This is in agreement with previous results obtained by Belakadem et al. [28] in a study of ultrathin nanoflake quantum dots using finite difference method.
El‐Yadri, A.
El Hadi, A.
El Hadi, M.
El-Miad.

Hence, in this letter, we will present an improved method for preparing such a single-layer EL polymer thin film.
However, the single layer blue light PLEDs fabricated in this section have the structure of ITO/PVK(100mg)+TPB(5mg)/LiF(10Å)/Ca(100Å)/Al(1000Å).
Configurations of the EL device and the molecules used.
The single-layer white light PLEDs fabricated in this section have the structure of ITO/PVK(100mg)+ TPB(5mg)+ rubrene(Xmg)/ LiF(10Å)/ Ca(100Å)/ Al(1000Å).
Conclusions In conclusion, an improved method for preparing single-layer EL thin films was presented.

El-Raghy, A.
El-Raghy, M.
El-Raghy, M.
El-Raghy, J.
El-Raghy, A.

Introduction Since the first report by Burroughes et al. in 1990 [1], flexible and tunable polymeric light-emitting diodes (PLED) based on conjugated polymers have been extensively investigated [2].
Tang et al. synthesized copolymers comprised of 9,9-dihexylfluorene and thieno [3,2-b] thiophene moieties using the Suzuki coupling reaction.
Their EL properties were summarized in table 1.
Figure 2 (right) shows the EL spectra of PLED based on the two polymers at a voltage of 6V.
EL Spectra Data and Performance Characteristics of the Devices polymer labs(nm)a lPL(nm)b lEL(nm)c fwhm (nm)d Lmax (cd/m2)e VT (V)f Ei (cd/A)g PFPh 360 494 510 108 2600 5.8 2.25 PFTDP 425 484 510 90 2300 6.5 1.13 aMaximum absorption in chloroform. b Maximum emission of PL spectra. c Maximum of EL spectra at a voltage of 6V. d The full width at half-maxiumu. e Maximum luminescence of EL. f Voltage needed for brightness of 1cd/m2. g Maximum current efficiency.

AL-Ghamdi1,a and Mohammad Yeakub Ali2,b 1Colleges and Institutes Sector, Royal Commission for Jubail, Saudi Arabia 2Department of Manufacturing and Materials Engineering, International Islamic University Malaysia, PO Box 10, 50728 Kuala Lumpur, Malaysia aur_goal123@hotmail.com, bmmyali@iium.edu.my Keywords: Nanocomposite, Multiwall carbon nanotube, High impact polystyrene, Water absorption Abstract.
(1) EI = EB - EL (2) If EL/EB ≤ 2.5 % => EL = 0 (3) (4) Where, Young's modulus, E; force applied to the object, F; original cross-sectional area through which the force is applied, A0; amount by which the length of the object changes, ΔL; original length of the object, L0; loss energy, EL; breaking energy, EB; impact energy for the test, EI; impact strength, I; cross sectional area, As.

Influence of Nanodispersions on Properties and Microstructure Features of Cast and T6 Heat-treated Al Si Hypoeutectic Alloys El Mahallawi1,a, H.
The present study aims to develop nano-dispersed Al-Si alloys with suitable casting methods that assure the dispersion of the nano-particles.
El- Mahallawi, Y.Shash, K.
Ragaie, A.Y.Shash and M.A.El Saeed.
Beygi; “Microstructure and mechanical properties of Al–Al2O3 micro and nano composites fabricated by stir casting”, Mater.

Regarding intermetallic particles, Fe-containing phases, as the brittle β-AlSiFe, usually present in casting alloys, are cathodic with respect to the Al matrix and, thus, contribute to corrosion phenomena at the interfaces with the Al matrix [5, 6].
In fact, Mn is reported to reduce the cathodic effect of Fe leading to a less intense reactions with the Al matrix [8, 9].
However, the effect of Cr and Mn on corrosion resistance of casting Al-Si-Mg alloys is hardly reported in literature.
[3] K.El-Menshawy, A.
El-Sayed, M.E.El-Bedawy, H.A.Ahmed and S.M.El-Raghy: Corros.

The fig.1 shows the structure of ZnS QDs EL device represented by phase segregation, the ZnS QDs distributed in a layer above the TPD: PMMA film.
The EL spectrum of the EL devices were measured at room temperature using fibre optic spectrometer CCS Series by THORLABS Company (Germany) which covering range from (200 - 1000) nm and the resolution of 1nm.
Fig. 6: EL of hybrid junction devices.
Holes are injected from the ITO anode into the HOMO of the TPD matrix and transported to the V.B; electrons are injected from the aluminum (Al) cathode into the C.B.
Table 2: EL coordinates for hybrid devices.