The Experts below are selected from a list of 56016 Experts worldwide ranked by ideXlab platform
A. Saatchi - One of the best experts on this subject based on the ideXlab platform.
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Effect of heat treatment on Corrosion Behavior of Ti–6Al–4V alloy weldments
Journal of Materials Processing Technology, 2008Co-Authors: Fathallah Karimzadeh, M. Heidarbeigy, A. SaatchiAbstract:Abstract In this study, the effect of preweld and postweld heat treatment on the Corrosion Behavior of Ti–6Al–4V alloy weldment was investigated. Gas tungsten arc welding (GTAW) was used for butt welding of specimens. In order to study the effects of heat treatment on the weldment microstructure and Corrosion properties, a combination of stress relieving, solution treatment and aging were used. Corrosion Behavior was determined in Ringer's solution at 37 °C using tafel polarization. Microstructure of base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) was studied with optical and scanning electron microscopy (SEM). The results of Corrosion tests showed that Corrosion Behavior of the BM was better than the FZ and HAZ. This phenomenon was attributed to alloying elements heterogeneity due to columnar-grain of the FZ and adjacent HAZ. Postweld heat treatment particularly solution treatment and aging improved the Corrosion Behavior of the weldments. Furthermore, uniformity in Corrosion potentials of different zones was achieved from the solution treatment and aging operation carried out subsequent to welding. This is due to the precipitation of α-phase from the small quantities of retained β and β-phase from the martensite, respectively. Heat treatment did not have any significant effect in improving the Corrosion Behavior of the BM.
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effect of tig welding on Corrosion Behavior of 316l stainless steel
Materials Letters, 2007Co-Authors: M H Fathi, M Dadfar, F Karimzadeh, A. SaatchiAbstract:Abstract 316L stainless steel (SS) is one of the most consumable materials in orthopedic implants. Certain types of orthopedic implants such as mono-bloc hip stems are often made of two elements welded together. In this study, effect of TIG welding on Corrosion Behavior of 316L stainless steel in physiological solution was investigated. In this method, filler metal wasn't used due to the small thickness of samples and it was welded to lap form. Corrosion Behavior in physiological solution at 37 °C was investigated with potentiodynamic polarization curves. Microstructure of base metal (BM) and weld metal (WM) was studied with scanning electronic microscopy (SEM). The Corrosion Behavior of weld metal, base metal and couple (BM and WM together) was compared together. For detecting microstructure and phases in BM and WM, X-ray diffraction analysis was done. Finally, post-weld heat treatment (PWHT) was performed on as-welded samples. Results indicated that Corrosion Behavior of WM was better than the BM. This phenomenon was attributed to secondary phases that were present in the BM. Secondary phases in the weld metal are dissolved when the base metal is melting due to the welding process. Based on the results of electrochemical analysis, it was determined that the Corrosion rate of a couple was more than of other parts. Heat affected zone (HAZ) is responsible for this phenomenon. The adjacent zones of the weld metal are classically less Corrosion resistant, thereby being attacked preferentially when the steel is exposed to corrosive environments. PWHT decreased the Corrosion rate of the couple.
T R Allen - One of the best experts on this subject based on the ideXlab platform.
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Corrosion Behavior of ni base alloys for advanced high temperature water cooled nuclear plants
Corrosion Science, 2008Co-Authors: Kumar Sridharan, T R AllenAbstract:Due to the projected requirement for highly enhanced efficiency in power generation, the environment in advanced high temperature water-cooled nuclear systems becomes more rigorous compared to conventional fossil and nuclear power plants. The Corrosion Behavior of candidate alloys Inconel 617, 625, and 718 exposed to supercritical water was studied by a variety of analytical techniques. Grain boundary engineering (GBE) was performed on the alloy 617 to compare its Corrosion Behavior with the as-received samples. The results indicate that the GBE-treated alloy 617 samples showed the best response and the alloy 718 samples showed the worst Corrosion resistance. Pitting observed on the alloy 718 samples was more serious than that on the alloy 625 samples. The effect of the alloying elements and the GBE treatment on the Corrosion Behavior is discussed.
Ying Yang - One of the best experts on this subject based on the ideXlab platform.
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Corrosion Behavior of alloy 800h fe 21cr 32ni in supercritical water
Corrosion Science, 2011Co-Authors: Todd R Allen, Ying YangAbstract:Abstract The effect of testing conditions (temperature, time, and oxygen content) and material’s microstructure (the as-received and the grain boundary engineered conditions) on the Corrosion Behavior of alloy 800H in high-temperature pressurized water was studied using a variety of characterization techniques. Oxidation was observed as the primary Corrosion Behavior on the samples. Oxide exfoliation was significantly mitigated on the grain boundary engineered samples compared to the as-received ones. The oxide formation, including some “mushroom-shaped oxidation”, is predicted via a combination of thermodynamics and kinetics influenced by the preferential diffusion of specific species using short-cut diffusion paths.
Kumar Sridharan - One of the best experts on this subject based on the ideXlab platform.
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Corrosion Behavior of ni base alloys for advanced high temperature water cooled nuclear plants
Corrosion Science, 2008Co-Authors: Kumar Sridharan, T R AllenAbstract:Due to the projected requirement for highly enhanced efficiency in power generation, the environment in advanced high temperature water-cooled nuclear systems becomes more rigorous compared to conventional fossil and nuclear power plants. The Corrosion Behavior of candidate alloys Inconel 617, 625, and 718 exposed to supercritical water was studied by a variety of analytical techniques. Grain boundary engineering (GBE) was performed on the alloy 617 to compare its Corrosion Behavior with the as-received samples. The results indicate that the GBE-treated alloy 617 samples showed the best response and the alloy 718 samples showed the worst Corrosion resistance. Pitting observed on the alloy 718 samples was more serious than that on the alloy 625 samples. The effect of the alloying elements and the GBE treatment on the Corrosion Behavior is discussed.
Abed Al S Jabab - One of the best experts on this subject based on the ideXlab platform.
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Corrosion Behavior of a new titanium alloy for dental implant applications in fluoride media
Materials Chemistry and Physics, 2004Co-Authors: Abdullah M. Al-mayouf, A. A. Al-swayih, N. A. Al-mobarak, Abed Al S JababAbstract:Abstract The effect of fluoride ion concentration and pH value on the Corrosion Behavior of Ti–30Cu–10Ag (wt.%) alloy, which is a new titanium alloy characterized by its low melting point, was examined by electrochemical methods in artificial saliva solutions. The Corrosion Behavior of pure Ti and Ti–6Al–4V were also examined for comparison. Fluoride ions affect the Corrosion Behavior of Ti and its alloys and the severity of the attack depends on both the concentration of fluoride ion and the pH value. High Corrosion rates were observed in neutral solutions with high fluoride concentrations and in acidic solutions with low fluoride concentrations. Increased fluoride concentration leads to increased thickness and/or porosity of the oxide layer, which reduces its Corrosion protection. The presence of Cu and Ag in the Ti–30Cu–10Ag alloy has a beneficial effect on its Corrosion Behavior, especially in acidic fluoride media.
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galvanic Corrosion Behavior of implant suprastructure dental alloys
Dental Materials, 2003Co-Authors: Nadia M Taher, Abed Al S JababAbstract:Abstract Objective . The purpose of this study was to evaluate and compare in vitro, the galvanic Corrosion Behavior of Co–Cr alloys (R2000, R800), Ni–Cr (RCS), silver–palladium (Jelstar), Gold (Pontallor-4) and Ternary Ti (experimental Ter Ti) when coupled with endosseous Ti implant abutment material. Amalgam alloy and commercially pure Ti cylinders (SSTi) were coupled with endosseous Ti implants as negative and positive controls, respectively. Method . An EG&G Model 263 Scanning Potentiostat was used for this purpose. Specimens were prepared and fresh artificial saliva was used as an electrolyte solution. The experiment run time was 24 h for each couple. The common potential, galvanic current and current integration during the last 6 h were recorded for each couple. Results . The results showed that the best couples were Ti/Pontallor-4, Ti/Ter Ti, Ti/R800 and Ti/Jelstar. The least acceptable couples were Ti/amalgam, SSTi/SSTi and Ti/R2000, while the Ti/RCS couple showed unstable galvanic Corrosion Behavior. Significance . It is concluded that the following alloys can be used as suprastructure alloys with Ti implants: Pontallor-4, R800, Jelstar and Ter Ti. Although Ter Ti alloy is an experimental alloy, it showed good results, but cannot be used in the clinical field unless extensive investigations are carried out. The SSTi/SSTi couple showed unexpected galvanic Corrosion Behavior which needs further investigation.
