Titanium nitride thin films were grown on 304 stainless steel substrates at various nitrogen/argon flow ratios by ion beam sputtering (IBS) technique. The current research is a follow up study on the influence of gas ratio on structural and Corrosion properties in the TiN coated 304 stainless steel. Film structural identification of phases was performed using X-ray diffractometry (XRD). Scanning electron microscope (SEM) was employed to study surface morphology and also elemental analysis of samples after Corrosion test was conducted by energy dispersive spectroscopy (EDS). Through our results, we showed that the films deposited under an Ar: N2 ratio of 50(sccm): 7(sccm) exhibited a TiN(200) preferred orientation. The Corrosion behavior of the samples was evaluated by potentiodynamic polarization test in 3. 5% NaCl solution. A critical gas ratio was found at which the Corrosion resistant was highest. The correlation between Corrosion resistance, structural and surface morphology was examined.

Copper is relatively soft metal and its wear and Corrosion are considered to be a major factors of degradation of this metal. For this reason, when the higher wear and Corrosion properties are needed, surface properties should be improved with different surface treatments. One of these methods is the applying of Ni-P electroless coating due to good mechanical properties, suitable Corrosion resistance and its ability of heat treatment on Cu. In this research after the surface preparation of Cu, which included grinding, degreasing and surface activation, the specimens were dipped into commercial electroless nickel bath (SLOTONIP 70A) for 60 minutes. SEM images and the results of the EDS test confirmed the formation of Ni-P electroless coating (with 10. 83 wt. % phosphorus) with a spherical structure. Applying the heat treatment increased the hardness of the coatings from 495 to 880 Vickers. XRD results showed this hardening is due to the formation of Ni crystal and Ni3P phases at this temperature in the coating. The study of wear resistance and Corrosion property of coatings was also done using pin-on test and polarization tests, respectively. The results showed that the heat treatment improved the wear resistance of the coating, and the weight loss in the presence of the heat treated coating reduced to 76% due to increasing hardness and roughness of the coating by performing heat treatment. This effect was also quite noticeable in the SEM images of the wear surfaces. The Corrosion results illustrated the Ni-P electroless coating significantly improved the Cu substrate Corrosion performance, due to the dense spherical structure and without any pores of the coating, and in particular the amorphous phase of the coating, but the heat treatment reduced the Corrosion property of the as deposited coating.

In this study, the mechanical, Tribological and Corrosion properties of Al6061 after different pass number of FSP were investigated. To study the microstructure of samples, optical microscopy (OM) and scanning electron microscopy (SEM) were used. Optical microscopy images showed that the average grain size of samples significantly decreased after FSP. Furthermore, results showed that using of FSP generally leads to the reduction of microhardness values, compared to the base metal. It can be deuced that there are various strengthening and weakening mechanisms governing on the mechanical properties of FSPed aluminum. In consistent with microhardness findings, Corrosion results showed that FSP has negative effects on the Corrosion resistance of Al6061. In other words, the polarization plots of FSPed samples shifted to the more negative potentials and higher current densities. Wear results are in good agreement with what was mentioned. In this regard, wear weight loss of two pass FSPed aluminum was about 3. 5 times higher than that for base metal.

The TiO2–SiO2 thin films were deposited on the AISI 316L stainless steel via the sol-gel method. Then, the effect of the added amount of SiO2 on the structure, morphology and mechanical properties of the films and Corrosion behavior of the AISI 316L stainless steel substrate were investigated Bu using X-ray diffraction, field-emission scanning electron microscopy, atomic force microscopy, depth-sensing indentation technique supporting micro-scratch mode and potentiodynamic polarization test. It was observed that the appropriate amount of SiO2 addition to the TiO2 film not only decreased the particle size of the TiO2–SiO2 crystal but also could help to improve the surface quality. Mechanical and Tribological properties of the films were found to be improved in the range of 10–15%mol of SiO2 addition compared with the pure TiO2. The minimum root mean square value was obtained from the film with a silica content of 10%mol. In addition, the Corrosion behavior of the AISI 316L stainless steel was improved by adding 15%mol of SiO2. Under the UV illumination conditions, photo-generated electrons accumulated in this film could perfectly protect the substrate photocathodically.

anodizing due to the significant increase in the surface performance of aluminum and its alloys is an appropriate method in the field of surface engineering. But for the application of this method as much as possible, filling the porosity of this coating is a very effective selection. On the other hand, due to the unique structure of the oxide layer, this layer can also be used to grow a variety of nanowires. In this study, 1070 aluminum anodizing was performed in oxalic acid-sulfuric acid solution. In order to reduce the thickness of the barrier layer, the anodizing voltage was slowly reduced in the last step of anodizing. Microstructure of the coating was studied by means of field emmision scanning electron microscopy (FESEM) images. Subsequently, silver nanowires were grown in the oxid layer by electrochemical deposition method. The result of X-ray diffraction(XRD) test showed that the oxide layer has a non-crystalline structure and silver nanowires has a very high purity. The hardness measurment of the samples showed that the presence of silver reduces the hardness of coating. The wear resistance of the coatings was investigated using a pin on disc test. The growth of silver in the oxid coating resulted in a 55% increase in the wear resistance. The scanning electron microscopy (SEM) images of the wear surfaces showed that this increase is related to silver lubrication nature that have reduced the coefficient of friction of the coating in the presence of these fillers. The effect of these nanowires on the Corrosion resistance of anodized aluminum was studied by using electrochemical impedance and polarization tests. The results showed that Corrosion behavior was improved slightly in the presence of silver nanowires.

In the present work, the effect of friction stir processing (FSP) on Tribological and mechanical properties as well as the Corrosion resistance of a low carbon steel (AISI 1010 (CK10)) is studied. FSP was successfully applied with different rotating speeds of 800-1600 rpm. Optimum properties was gained for the sample which was processed with the minimum rotating speed of 800 rpm. Metallographic study of this sample showed that dynamic recrystallization has decreased the average grain size to about 0. 5 μ m, while the initial value was ~10 μ m. The tensile strength of the optimal specimen increased for about 50 MPa. Also, the hardness of the processed samples was about 2. 5 times that of the raw material. As the result of grain refinement and the improvement of mechanical properties, the Tribological properties of the sample were also improved such that a 28% reduction in the wear rate was observed. Finally, Corrosion tests (according to ASTM G5) showed that FSP has no considerable influence on the Corrosion resistance of the studied steel.

High Corrosion resistance, proper mechanical properties, and biocompatibility of Ti-6Al-4V alloy make it suitable for medical (dentistry and orthopedic implants), military and electronic industries. The greatest disadvantages of this alloy are poor wear resistance, low fatigue strength and poor Tribological properties. The aim of this study was to apply an adhesive coating to improve both Corrosion and wear properties of the Ti-6Al-4V alloy. Surface modification of alloy was done by nitrogen plasma nitriding in both electrolyte plasma and atmosphere plasma environment. Finally, the TiN layer was coated on the modified samples, using cathodic arc evaporation technique. The microstructural investigation, surface morphology, and coating thickness were studied by field emission scanning electron microscope (FESEM) equipped with energy dispersive spectroscopy. The grazing incidence X-ray diffraction (GIXRD) was applied to study the phases in the coatings. The Corrosion resistance was studied with potentiodynamic polarization and electrochemical impedance spectroscopy. The wear resistance and the coating coefficient of friction were tested with pin-on-disc machine. The Corrosion resistance of the samples was improved by applying the coatings and the plasma-nitride/TiN double-layer coating showed the best Corrosion resistance with current density of 1. 46×10-7A/cm2 and Corrosion potential of-0. 3V. On the other hand, the lowest thickness reduction in wear test was observed in double-layer coatings, so that the thickness reduction for both double-layer coatings, was less than 4μ m, after 300m sliding.

Industrial equipment's lifetime and efficiency depend mainly on its structures and performances in the harsh conditions of aggressive environments. Therefore, the protection of the equipment's surface is significant. In recent decades, multi-component hard coatings have been highly regarded in scientific and industrial communities. Different types of transition metal-based multi-component coatings, such as coatings based on chromium, titanium, and refractory metals, have been widely used as protective coatings. However, other components of these coatings (such as carbon, nitrogen, and silicon), surface morphology, and grain size will play essential roles in their properties and applications. For example, two-component transition-metal nitride coatings can not be used in abrasion conditions, while transition-metal carbide coatings are a significant candidate. However, three-component transition-metal Carbonitride coatings can provide better mechanical properties and Tribological performances than Two-component coatings. On the other hand, some properties of transition metal-based coatings, such as oxidation resistance, residual stress, and frictional performance, can be significantly improved by doping silicon (Si).

Industrial equipment's lifetime and efficiency depend mainly on its structures and performances in the harsh conditions of aggressive environments. Therefore, the protection of the equipment's surface is significant. In recent decades, multi-component hard coatings have been highly regarded in scientific and industrial communities. Different types of transition metal-based multi-component coatings, such as coatings based on chromium, titanium, and refractory metals, have been widely used as protective coatings. However, other components of these coatings (such as carbon, nitrogen, and silicon), surface morphology, and grain size will play essential roles in their properties and applications. For example, two-component transition-metal nitride coatings can not be used in abrasion conditions, while transition-metal carbide coatings are a significant candidate. However, three-component transition-metal Carbonitride coatings can provide better mechanical properties and Tribological performances than Two-component coatings. On the other hand, some properties of transition metal-based coatings, such as oxidation resistance, residual stress, and frictional performance, can be significantly improved by doping silicon (Si).