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

Prevention of infection and bioactivity of implantable parts in the body is one of the most important issues investigated in medical research in recent years. In this regard, researchers have conducted many studies in order to increase the bioactivity of implantable parts in the body. Increasing the bioactivity of these parts has been done in different ways, while coating the surface of the parts is considered as one of the best methods in this field. In this research, simultaneous coating of iron oxide nanoparticles (magnetite) along with 45S5 bioactive glass on AISI 316 stainless steel substrate was deposited by electrophoretic method to increase the bioactivity and the possibility of hyperthermic applications. X-ray diffraction analysis confirmed the presence of both iron oxide nanoparticles and bioactive glass. Electron microscope was employed to study the coating surface. Conducting surface investigations by surface roughness and wetting angle measurements, it was shown that the roughness of the coated surface was 49.2±1 µm and the wetting angle of this coating was obtained to be 49°. The results declared that this coating had a surface with medium roughness and hydrophilic properties, which was of great importance for bioactivity performance. Investigating the magnetic properties of the coating, magnetometric evaluation was performed on the synthesized samples. The saturation magnetization and the Hc parameter values of the coating were obtained to be 20.2 emu/g and 89 Gauss, respectively.

In the present study, hydroxyapatite (HA) Single layer TiO2 single layer, HA-TiO2 double layer and functionally graded HA/TiO2 coatings were deposited on Ti-6Al-4V titanium alloy substrate by electrophoretic deposition technique (EPD). Impact resistance of coatings were measured by ball drop impact test and the results showed that the HA/TiO2 functionally graded coating has more impact resistance compare to HA single layer and HA-TiO2 double layer coatings. The wear resistance of coatings were investigated by pin on disc method. The normal load and sliding distance were 0.5 N and 50 m respectively and the worn surface was observed using scanning electron microscope (SEM) and analyzed by ImageJ software. The results showed that the HA/TiO2 functionally graded coating has more wear resistance compare to HA single layer. Additionally, investigation of worn surface of coatings showed that all of the coatings have abrasive mechanism but wear mechanism for functionally graded coating, changed and delamination was added to abrasive mechanism.

Single layer and functionally graded coatings of hydroxyapatite and TiO2 particles were deposited on Ti-6Al-4V titanium alloy substrate by electrophoretic deposition technique (EPD). The coatings chemical composition and morphology were investigated using energy dispersive X-ray spectroscopy (EDX), scanning electron microscope (SEM) and X-ray diffraction (XRD) methods. The results showed in HA/TiO2 functionally graded coating, the composition varied from inner layer to top layer as 100 %wt TiO2 to 100 %wt HA. To investigation biocompatibility of the coatings, the culture Wharton’s Mesenchymal Stem Cells was used. The results showed the HA/TiO2 functionally graded coating and HA single layer coating were more biocompatible in comparison to TiO2 single layer coating. The adhesion strengths of the coatings were measured by shear testing and the results showed that the HA/TiO2 functionally graded coating has more adhesion strength (~31 MPa) compare to HA single layer.

Anodic oxidation can be done in order to obtain a porous structure، and to obtain TiO2 nanotubes. In the current research، first، titanium dioxide nanotubes were fabricated by anodic oxidation and then hydroxyapatite nanoparticles have been deposited onto nanotublar TiO2 by electrophoretic deposition at 30V for 10min and then sintered at 400°С for 2hr. Corrosion behavior in SBF at 37˚С was evaluated. The results show that formation of TiO2 nanotubes and sintering improve corrosion behavior in SBF.

In this research, HA-TiO2 and HA-TiO2-CNT nanocomposite coated on 316L stainless steel substrates by electrophoretic method. In order to making a stable suspension, isopropanol was used as solvent and tri-ethanol amine as dispersant. Microstructure and particle distribution of nanoparticles were characterized by scanning electron microscopy (SEM) and elemental sputtering, respectively. Effect of carbon nanotube and titanium oxide nanoparticles on hardness and elastic modulus of nanocomposite coatings were compared by nanohardness curves of coatings. Morphology, topography and surface roughness of coatings were observed by Field Emission Scanning Electron Microscopy (FESEM) and Atomic force microscopy (AFM).

Electrophoretic deposition has been used by establishing an electric field in a stable suspension, a perfectly smooth and uniform surface is obtained. In this study a coating is applied on a Inconel substrate by the ionizations of alumina single crystals in a suspension and in an electric field. Then, with sintering treatment, a dense coating is obtained. The effect of time, applied voltage, processing, sintering temperature, and the pH of the solution on the thickness of deposited layer are also investigated. To determine the thickness and analysis of coating layer, scanning electron microscopy was used.It was found that by increasing voltage, applied current, sintering temperature and also applying optimum processing of sintering treatment and increasing pH, the thickness of deposited layer was increased. Each of the mentioned factors had different effects on the thickness of coating layer. With due attention to the effective factors on the thickness of the deposited layer, optimum conditions for applying coating was achieved.