A. Noorian, Sh. Kheirandish, H. Saghafian,
Volume 7, Issue 2 (Spring 2010 2010)
Abstract
Abstract:
mechanical properties of AISIH 13 hot-work tool steel have been studied. Cast samples made of the modified new steel were homogenized and austenitized at different conditions, followed by tempering at the specified temperature ranges. Hardness, red hardness, three point bending test and Charpy impact test were carried out to evaluate the mechanical properties together with characterizing the microstructure of the modified steel using scanning electron microscope. The results show that niobium addition modifies the cast structure of Nb–alloyed steel, and increases its maximum hardness. It was found that bending strength bending strain, impact strength, and red hardness of the modified cast steel are also higher than those of the cast H13 steel, and lower than those of the wrought H13 steel.
In this research, the effects of partially replacing of vanadium and molybdenum with niobium on the
S. Noori, J. Khalil-Allafi,
Volume 12, Issue 2 (June 2015)
Abstract
The effect of anodic oxidation of a NiTi shape memory alloy in sulfuric acid electrolyte on its surface
characteristics was studied. Surface roughness was measured by roughness tester. Surface morphology was studied
using optical microscopy (OM) and scanning electron microscopy (SEM). Corrosion behavior was specified by
recording Potentiodynamic polarization curves and measuring the content of Ni ions, released into a SBF solution
using atomic absorption spectroscopy (AAS). Fourier transformation infrared radiation (FT-IR) and energy dispersive
spectroscopy were employed to verify the biocompatibility of the anodized and bare alloys after submersion in SBF. It
was shown that anodic oxidation in sulfuric acid significantly increases corrosion resistance and biocompatibility. This
layer improves corrosion resistance and Ni ion-release resistance by impeding the direct contact of the alloy with the
corrosion mediums i.e. Ringer and SBF solutions. The TiO2 oxide layer also decreases the releasing of Ni ions in to
SBF solution
Pooyan Soroori, Saeid Baghshahi, Arghavan Kazemi, Nastaran Riahi Noori, Saba Payrazm, Amirtaymour Aliabadizadeh,
Volume 19, Issue 3 (September 2022)
Abstract
The goal of the present study is to prepare a room temperature cured hydrophobic and self-cleaning nano-coating for power line insulators. As a result, the installed insulators operating in power lines can be coated without being removed from the circuit and without the need to cut off power. For this purpose, hydrophobic silica nanoparticles were synthesized by sol-gel method using TEOS and HMDS. The synthesized hydrophobic silica nanoparticles were characterized by XRD, FTIR, SEM, and TEM analyses to investigate phase formation, particle size, and morphology. Then the surface of the insulator was cleaned and sprayed by Ultimeg binder solution, an air-dried insulating coating, as the base coating. Then the hydrophobic nano-silica powder was sprayed on the binder coated surface and left to be air-cured at room temperature. After drying the coating, the contact angle was measured to be 149o. Pull-off test was used to check the adhesion strength of the hydrophobic coating to the base insulator. To evaluate the effect of environmental factors, UV resistance and fog-salt corrosion tests were conducted. The results showed that 150 hours of UV radiation, equivalent to 9 months of placing the samples in normal conditions, did not have any significant effect on reducing the hydrophobicity of the applied coatings.
