Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Electrical conductivity

Multiwall Carbon Nanotube / Polyvinyl Alcohol Nanofibers Film, Electrical Conductivity Improvement

Akram R. Jabur

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 431-439
DOI: 10.30684/etj.v38i3A.530

Conductive polymer films were prepared of polyvinyl alcohol (PVA) with (0, 2, 4, 6, 8, and 10) wt. % multiwalled carbon nanotubes (MWCNTs) by electrospinning technique. The morphologies of the synthesized films were tested by scanning electron microscopy (SEM). Average fiber diameters gauged statically was (115nm) for (PVA/10 wt. % MWCNT film) while (170nm) for pure PVA electro spun film. Electrical conductivity (EC) of Polymeric nanofiber films improve by increasing MWCNT addition concentration from (3.69 × 10-7 S/ cm) for the pure (PVA) film to (1.24 ×10-2 S/cm) for the film with 10 wt. % MWCNT. The maximum stress of PVA film were increased by adding MWCNTs concentration, the modulus of elasticity was enhanced from 12.87 MPa for pure PVA to 49.89 MPa for PVA/8wt% MWCNT.

Investigation the Creep-Fatigue Behavior and A.C. Electrical Conductivity of AA 6061 Under Ultrasonic Peening

Hussain J. Al-Alkawi; Ahmed H. Reja; Mahmood F. Abbas

Engineering and Technology Journal, 2019, Volume 37, Issue 11A, Pages 453-459
DOI: 10.30684/etj.37.11A.1

Ultrasonic peening is an innovative surface improvement process used to increase the resistance of aircraft metals and enhance high cycle fatigue life. The process creates residual compressive stresses deep into part surfaces. These compressive surface stresses inhibit the initiation and propagation of fatigue cracks. Aluminum alloys are relatively new materials used in aerospace, marine, automobile, and bridges due to low weight, which has significant advantages compared to the other materials. A major concern in the design of Aluminum alloys subjected to variable loads is fatigue strength and life. In this paper mechanical properties, fatigue strength, fatigue life and A.C.. electrical conductivity were studied for AA6061-T6 to assess the effects of ultrasonic peening (UP) on mechanical properties, fatigue at room temperature (RT), creep-fatigue (CF) at 250 ͦC and A.C.. electrical conductivity. Test results showed that after UP, the mechanical properties; ultimate tensile strength (UTS) and yield stress (Ys) were noticeably improved. The improvements in UTS and Ys were enhanced by 5.7% and 1.5% respectively while the ductility was reduced from 16.5% to 15.7%. Fatigue strength was enhanced by 8.37% compared to strength at RT. The results of UT before creep-fatigue CF showed increasing in fatigue strength 147 MPa at CF 250 ̊C and improved to153 MPa after applying UP, indicating 4% improvement in strength. The fatigue life was improved after UP for both RT and CF. It was found that the A.C. electrical conductivity increase as the frequency increase for all the cases above.

Microstructure and Electrical Conductivity of 7075Al alloy/SiC Nano Composites

Hussain J. Al-Alkawi; Sameir A. Aziez; Deana A. Idan

Engineering and Technology Journal, 2018, Volume 36, Issue 10A, Pages 1034-1038
DOI: 10.30684/etj.36.10A.3

Analysis using scanning electron microscope (SEM) at high magnification showed that the microstructure of the nano composites exhibited uniform distribution of SiC particles and less porosity. The experimental results revealed that adding Nano Reinforcement to 7075Al alloy improve the electrical conductivity for the metal matrix composites with 3, 6, 9 wt. % SiC were adopted in this work. The maximum enhancements were observed at 9wt. %SiC of 5200(Ω. m) -1 compared with the metal base of 35 (Ω. m) -1.

Synthesis and Study of the Structural and Electrical Conductivity for Nanocrystalline PbS Thin Films

Ali M. Mousa; Selma M. Al-Jawad; SuadM.Kadhim Al-shammari

Engineering and Technology Journal, 2013, Volume 31, Issue 6, Pages 714-719

Structural and electrical properties of prepared nanocrystalline lead sulfide thin films were studied which deposited on glass substrates by chemical bath deposition (CBD) techniques. The films were obtained in a reaction bath at times of (15, 30, 45,60and90) min. The X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements confirmed that the thin films grown by this technique had good crystalline cubic structures and homogeneous surfaces. The dc electrical conductivity found in the range of 10-6 -10-5 (Ω.cm)-1.