جستجوی مقالات مرتبط با کلیدواژه « زبری سطحی » در نشریات گروه « مواد و متالورژی »

Shot peening as a surface treatment is a process that by bombardment of shots on the metal surface, creates plastic deformation and compressive residual stresses beneath the surface. On the other hand, aluminum alloys for having high strength against weight ratio and good corrosion resistance, as compared to other metals, is utilized in sea industries. The present paper investigates the effect of shot peening on the surface layers properties such as surface roughness, surface layers hardness, and the effect of formed compressive residual stresses on behavior of corrosion fatigue of 7075-T6 aluminum alloy in sea environment. For this purpose, surface of the aluminum specimens were prepared under the tossed balls and plastic deformation on the surface was created. The residual stresses in the subsurface layers were formed. Roughness and hardness of the surface layer was measured by micro hardness and roughness tester machine. The polished and shot peening specimens under the rotating fatigue corrosion are tested. The obtained results by the research show the increase of surface layers hardness, surface roughness, corrosion fatigue life time, and strength of the alloy by shot clashes and compressive residual stresses resulting from shot peening process compared to polishing specimens.

In this report a facile and optimized method for polishing of fluorine doped tin oxide (FTO) was presented in which nanoparticles in toothpaste was used as polishing material. Due to being more chemically and physically stability relative to another TCO such as indium tin oxide (ITO), FTO is used in optoelectronic devices. More thickness in FTO due to have a good conductivity resulting a rough surface. Toothpaste can make smooth FTO surface due to have polisher nanoparticles. Here, FTO surface was smooth using toothpaste so that according to AFM data, the RMS surface roughness was changed from 12 nm for FTO to 3 nm for FTO after polishing. The comparing of the transmittance spectra FTO before and after polishing process showed the FTO thickness was not changed dramatically. The X-Ray photoelectron spectroscopy showed there were no effects on the chemical states of FTO surface before and after polishing process. The hybrid light emitting diode was fabricated using polished FTO that it was more efficient comparing to those fabricated with FTO and ITO.