A full factorial design of experiment was applied in running 36 experiments to investigate the effect of milling parameters including cutting speed, feed rate, cutting depth and machining media at two levels, on surface integration properties of magnesium AZ91C alloy such as grain size, secondary phase content, surface microhardness and roughness. In all cases, a fine grained surface with higher secondary phase sediment and microhardness was obtained in comparison to the raw material. According to analysis of variance results, the most effective parameter on grain size, secondary phase percent and microhardness was cutting depth and the most effective parameter on surface roughness was the feeding rate. although the grain size in all machined samples was smaller than that of the raw material but due to the dual effect of cryogenic conditions, which both cool and lubricate and reduce the temperature and strain rate at the same time, the direct effect of this parameter on grain size was not significant. The collective effect of parameters on grain size and microhardness was also significant.
{"title":"The Influence of Milling Parameters on Surface Properties in Milled AZ91C Magnesium Alloy","authors":"A. Mostafapour, M. Mohammadi, A. Ebrahimpour","doi":"10.22068/IJMSE.1971","DOIUrl":"https://doi.org/10.22068/IJMSE.1971","url":null,"abstract":"A full factorial design of experiment was applied in running 36 experiments to investigate the effect of milling parameters including cutting speed, feed rate, cutting depth and machining media at two levels, on surface integration properties of magnesium AZ91C alloy such as grain size, secondary phase content, surface microhardness and roughness. In all cases, a fine grained surface with higher secondary phase sediment and microhardness was obtained in comparison to the raw material. According to analysis of variance results, the most effective parameter on grain size, secondary phase percent and microhardness was cutting depth and the most effective parameter on surface roughness was the feeding rate. although the grain size in all machined samples was smaller than that of the raw material but due to the dual effect of cryogenic conditions, which both cool and lubricate and reduce the temperature and strain rate at the same time, the direct effect of this parameter on grain size was not significant. The collective effect of parameters on grain size and microhardness was also significant.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47977035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Namrata Saxena, Varshali Sharma, Ritu Sharma, K. K. Sharma, K. K. Jain
The work reported in this paper was focused on the investigation of surface morphological, microstructural, and optical features of polycrystalline BaTiO3 thin film deposited on p-type Si < 100 > substrate using e-beam PVD (physical vapor deposition) technique. The influence of annealing on the surface morphology of the thin film was analyzed by X-ray diffraction, atomic force microscopy and scanning electron microscopy. When the annealing temperature was increased from as-deposited to 800 °C there was a significant growth in the grain size from 28.407 to 37.89 nm. This granular growth of BaTiO3 made the thin film appropriate for nanoelectronic device applications. The roughness of the annealed film was increased from 31.5 to 52.8 nm with the annealing temperature. The optical bandgap was computed using Kubelka-Munk (KM) method which was reduced from 3.93 to 3.87 eV for the as-deposited to the 800 °C annealed film. The above reported properties made the annealed film suitable for optoelectronic applications. For polycrystalline BaTiO3 thin film the refractive index varied from 2.2 to 1.98 from 400 to 500 nm and it was 2.05 at 550 nm wavelength. The broad peaks in Raman spectra indicated the polycrystalline nature of the thin film. It was also observed that with the annealing temperature the intensity of the Raman peaks increased. From these results, it was proved that annealing significantly improved the crystallinity, microstructural, surface morphological and optical features of the barium titanate thin film which made it suitable as potential sensors in biomedical applications as it is cost-effective, lead-free and environment friendly material.
{"title":"The Effect of Thermal Annealing on Structural, Morphological and Optical Features of BaTiO3 Thin Film assisted by e-beam PVD Technique","authors":"Namrata Saxena, Varshali Sharma, Ritu Sharma, K. K. Sharma, K. K. Jain","doi":"10.22068/IJMSE.1879","DOIUrl":"https://doi.org/10.22068/IJMSE.1879","url":null,"abstract":"The work reported in this paper was focused on the investigation of surface morphological, microstructural, and optical features of polycrystalline BaTiO3 thin film deposited on p-type Si < 100 > substrate using e-beam PVD (physical vapor deposition) technique. The influence of annealing on the surface morphology of the thin film was analyzed by X-ray diffraction, atomic force microscopy and scanning electron microscopy. When the annealing temperature was increased from as-deposited to 800 °C there was a significant growth in the grain size from 28.407 to 37.89 nm. This granular growth of BaTiO3 made the thin film appropriate for nanoelectronic device applications. The roughness of the annealed film was increased from 31.5 to 52.8 nm with the annealing temperature. The optical bandgap was computed using Kubelka-Munk (KM) method which was reduced from 3.93 to 3.87 eV for the as-deposited to the 800 °C annealed film. The above reported properties made the annealed film suitable for optoelectronic applications. For polycrystalline BaTiO3 thin film the refractive index varied from 2.2 to 1.98 from 400 to 500 nm and it was 2.05 at 550 nm wavelength. The broad peaks in Raman spectra indicated the polycrystalline nature of the thin film. It was also observed that with the annealing temperature the intensity of the Raman peaks increased. From these results, it was proved that annealing significantly improved the crystallinity, microstructural, surface morphological and optical features of the barium titanate thin film which made it suitable as potential sensors in biomedical applications as it is cost-effective, lead-free and environment friendly material.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43004301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Gouitaa, Lamcharfi Taj-dine, Bouayad Lamfaddal, A. Farid, M. Ounacer, M. Sajieddine
The structural and dielectric properties of iron and bismuth co-substituted BaTiO3 ceramic with the formula: B0.95Bi0.05Ti1-xFexO3 for x=0.00 to 1.00, synthesis with solid state route, were characterized. The X-ray diffraction results show a tetragonal phase for x=0.00. While for x=0.40 to 0.80 we observed a coexistence of tree phase tetragonal, hexagonal and pseudo-cubic. And at x=1.00 only the pseudo-cubic phase is present and the other phase disappeared. The Raman results indicate the existence of tetragonal band for x≤0.40, and an appearance of characteristic bands of Fe3+ ions for more than 0.40 of Fe content. The SEM micrographs show an increase in grain size with the increase of Fe content and it reaches a maximum at x=0.40. And the Mossbauer spectroscopy indicates that our samples is paramagnetic at room temperature and that the Fe is oxidized under Fe3+ with no existence of Fe2+ and Fe4+ ions. The temperature dependence of dielectric permittivity was investigated in the frequency range from 20 Hz to 2MHz. The results show three dielectric relaxation phase transitions from a rhombohedral ferroelectric to orthorhombic ferroelectric (TR-O) then to a tetragonal ferroelectric phase (at TO-T), and finally to cubic paraelectric at the Curie temperature (TC). In addition, the temperature of phase transition shifted to the lower temperature with the increase of Fe content for all the phase transitions. And the maximum of dielectric permittivity increases for TR-O while for TT-O and Tm phases transitions, it reaches a maximum at x=0.60 and x=0.80 respectively and then decreases.
{"title":"The Study of Structure and Transitional Phases in B0.95Bi0.05Ti1-xFexO3 Ceramics Synthesized by Solid State Route","authors":"N. Gouitaa, Lamcharfi Taj-dine, Bouayad Lamfaddal, A. Farid, M. Ounacer, M. Sajieddine","doi":"10.22068/IJMSE.2058","DOIUrl":"https://doi.org/10.22068/IJMSE.2058","url":null,"abstract":"The structural and dielectric properties of iron and bismuth co-substituted BaTiO3 ceramic with the formula: B0.95Bi0.05Ti1-xFexO3 for x=0.00 to 1.00, synthesis with solid state route, were characterized. The X-ray diffraction results show a tetragonal phase for x=0.00. While for x=0.40 to 0.80 we observed a coexistence of tree phase tetragonal, hexagonal and pseudo-cubic. And at x=1.00 only the pseudo-cubic phase is present and the other phase disappeared. The Raman results indicate the existence of tetragonal band for x≤0.40, and an appearance of characteristic bands of Fe3+ ions for more than 0.40 of Fe content. The SEM micrographs show an increase in grain size with the increase of Fe content and it reaches a maximum at x=0.40. And the Mossbauer spectroscopy indicates that our samples is paramagnetic at room temperature and that the Fe is oxidized under Fe3+ with no existence of Fe2+ and Fe4+ ions. The temperature dependence of dielectric permittivity was investigated in the frequency range from 20 Hz to 2MHz. The results show three dielectric relaxation phase transitions from a rhombohedral ferroelectric to orthorhombic ferroelectric (TR-O) then to a tetragonal ferroelectric phase (at TO-T), and finally to cubic paraelectric at the Curie temperature (TC). In addition, the temperature of phase transition shifted to the lower temperature with the increase of Fe content for all the phase transitions. And the maximum of dielectric permittivity increases for TR-O while for TT-O and Tm phases transitions, it reaches a maximum at x=0.60 and x=0.80 respectively and then decreases.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48440274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, the early stages of the surface oxidation and fluoridation of liquid AZ91D and AM60B alloys under ultra-high purity (UHP) argon, dry air, and air mixed with two different protective fluorine-bearing gases were studied. The chemical composition, morphology and thickness of the surface films formed inside the trapped bubbles were characterized by SEM equipped with EDS analysis. It is found that the molten AM60B alloy is more sensitive to impurities under UHP argon gas than AZ91D alloy. Under dry air atmosphere, the entire surface of molten AZ91D alloy is covered with an oxide layer and thinner thickness than the surface film formed on AM60B alloy which has rough surface exhibiting granular growth in later stages of oxidation. The EDS analysis shows that the film chemistry is mainly composed of Mg, Al and O elements. Under fluorine-bearing gas/air mixtures with either SF6 or HFC-R134a at 3.5%vol., a fresh surface film formed with a flat and dense morphology with a uniform thickness consisting of Mg, F, Al and O elements. It is observed that there is a lower O:F intensity ratio in the surface film formed on the molten AZ91D alloy under 1,1,1,2-tetra-fluoroethane (HFC-R134a) mixed with dry air compared to the AM60B alloy under both air/ R134a and air/SF6 mixtures which shows a higher fluorine concentration in the surface film a leading to a better oxidation resistance.
{"title":"Characterization of the Early Surface Films Dynamically Formed on Molten AZ91D and AM60B Alloys Under Different Atmospheres: A Comparative Study","authors":"A. Mirak","doi":"10.22068/IJMSE.1570","DOIUrl":"https://doi.org/10.22068/IJMSE.1570","url":null,"abstract":"In the present study, the early stages of the surface oxidation and fluoridation of liquid AZ91D and AM60B alloys under ultra-high purity (UHP) argon, dry air, and air mixed with two different protective fluorine-bearing gases were studied. The chemical composition, morphology and thickness of the surface films formed inside the trapped bubbles were characterized by SEM equipped with EDS analysis. It is found that the molten AM60B alloy is more sensitive to impurities under UHP argon gas than AZ91D alloy. Under dry air atmosphere, the entire surface of molten AZ91D alloy is covered with an oxide layer and thinner thickness than the surface film formed on AM60B alloy which has rough surface exhibiting granular growth in later stages of oxidation. The EDS analysis shows that the film chemistry is mainly composed of Mg, Al and O elements. Under fluorine-bearing gas/air mixtures with either SF6 or HFC-R134a at 3.5%vol., a fresh surface film formed with a flat and dense morphology with a uniform thickness consisting of Mg, F, Al and O elements. It is observed that there is a lower O:F intensity ratio in the surface film formed on the molten AZ91D alloy under 1,1,1,2-tetra-fluoroethane (HFC-R134a) mixed with dry air compared to the AM60B alloy under both air/ R134a and air/SF6 mixtures which shows a higher fluorine concentration in the surface film a leading to a better oxidation resistance.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45658467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chimmachandiran Suresh Kumar, K. Dhanaraj, R. Vimalathithan, P. Ilaiyaraja, G. Suresh
The Nano Hydroxyapatite (HAp), HAp/PEG and HAp/PVP powders derived from both Gastropod shell (natural source) and chemical precursor by the precipitation method were characterized through various characterization techniques such as FT-IR, XRD, SEM-EDX, TEM, Antibacterial activity and SBF analysis. Based on the structural, chemical, morphological and biological characteristics, HAp/PVP from natural and chemical precursors have been compared. Calculated structural parameters, crystallinity index, C/P ratio, morphology, antibacterial activity and SBF analysis of the products show that HAp/PVP-S (derived from a natural source) exhibits good mechanical property, rod like morphology, good antibacterial activity and apatite formation ability after 14 days. EDX analysis also shows the presence of carbon and sodium in HAp/PVP-S. Comparative analysis reveals that characteristics of HAp/PVP-S such as high carbonate content, low crystallite size, poor crystalline nature, presence of trace metal, non-stoichiometric elemental composition and rod like crystals which are matched with the characteristics of biological apatite. Thus, the HAp/PVP-S has the ability to form bone apatite.
{"title":"Structural, Morphological and Anti-bacterial Analysis of Nanohydroxyapatite Derived from Biogenic (SHELL) and Chemical Source: Formation of Apatite","authors":"Chimmachandiran Suresh Kumar, K. Dhanaraj, R. Vimalathithan, P. Ilaiyaraja, G. Suresh","doi":"10.22068/IJMSE.18.1.10","DOIUrl":"https://doi.org/10.22068/IJMSE.18.1.10","url":null,"abstract":"The Nano Hydroxyapatite (HAp), HAp/PEG and HAp/PVP powders derived from both Gastropod shell (natural source) and chemical precursor by the precipitation method were characterized through various characterization techniques such as FT-IR, XRD, SEM-EDX, TEM, Antibacterial activity and SBF analysis. Based on the structural, chemical, morphological and biological characteristics, HAp/PVP from natural and chemical precursors have been compared. Calculated structural parameters, crystallinity index, C/P ratio, morphology, antibacterial activity and SBF analysis of the products show that HAp/PVP-S (derived from a natural source) exhibits good mechanical property, rod like morphology, good antibacterial activity and apatite formation ability after 14 days. EDX analysis also shows the presence of carbon and sodium in HAp/PVP-S. Comparative analysis reveals that characteristics of HAp/PVP-S such as high carbonate content, low crystallite size, poor crystalline nature, presence of trace metal, non-stoichiometric elemental composition and rod like crystals which are matched with the characteristics of biological apatite. Thus, the HAp/PVP-S has the ability to form bone apatite.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47653959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Translucent porcelain with appropriate workability has been considered beneficial for light and shadow to be used in the production of ceramic artworks. In addition, using low firing temperature encourages more artists to use this body. The soft-paste cellulose composite porcelain is composed of similar amount of high borax/calcia leadless frit and kaolin with 3% Vee gum T as a plasticizer. In order to increase workability and green strength, five volume units of soft-paste porcelain (SP) slip was mixed with one volume unit bleached bagasse pulp of sugar cane slip and then cellulose containing soft-paste porcelain (CSP) slip was made. The samples were formed by hand, dried and then fired at the optimum temperature of 1120 for 5 hours. Results showed that the SP sample became self-glazed after firing. Adding 20% paper pulp by 1.4 ⁄ density in volume to porcelain body slip (1.36 g cellulose fiber in 100 g SP) slightly increased transmission of light. Microstructure analysis showed a large amount of glass phase, which improved translucency of the bodies. Moreover, mullite needle shaped crystals were formed via reaction of clay and molten flux due to low melt viscosity. XRD results clearly showed that the fired soft-paste porcelain contained quartz, mullite, anorthite and albite in the fired state.
具有适当可加工性的半透明瓷器被认为有利于在陶瓷艺术品的生产中使用光影。此外，使用较低的烧制温度鼓励更多的艺术家使用这种身体。软浆状纤维素复合瓷是由等量的高硼砂/钙无铅玻璃料和高岭土组成，并以3%的Vee胶T为增塑剂。为了提高可加工性和生坯强度，将5体积单位的软浆瓷浆（SP）与1体积单位的甘蔗浆漂白蔗渣浆混合，制成了含纤维素的软浆陶瓷浆（CSP）。用手形成样品，干燥，然后在1120的最佳温度下烧制5小时。结果表明，烧结后的SP样品具有自上釉性。将体积密度为1.4⁄的20%纸浆添加到瓷身滑片中（100 g SP中含有1.36 g纤维素纤维），略微增加了透光率。微观结构分析表明，大量的玻璃相存在，提高了基体的透光性。此外，由于熔体粘度低，粘土和助熔剂反应形成了莫来石针状晶体。XRD结果清楚地表明，烧制的软质瓷在烧制状态下含有石英、莫来石、钙长石和钠长石。
{"title":"The Microstructure and Translucency Investigation of Cellulose Containing Low Temperature Fritted Soft-paste Porcelain","authors":"M. Mianji, H. Sarpoolaky, M. S. Sararoudi","doi":"10.22068/IJMSE.18.1.4","DOIUrl":"https://doi.org/10.22068/IJMSE.18.1.4","url":null,"abstract":"Translucent porcelain with appropriate workability has been considered beneficial for light and shadow to be used in the production of ceramic artworks. In addition, using low firing temperature encourages more artists to use this body. The soft-paste cellulose composite porcelain is composed of similar amount of high borax/calcia leadless frit and kaolin with 3% Vee gum T as a plasticizer. In order to increase workability and green strength, five volume units of soft-paste porcelain (SP) slip was mixed with one volume unit bleached bagasse pulp of sugar cane slip and then cellulose containing soft-paste porcelain (CSP) slip was made. The samples were formed by hand, dried and then fired at the optimum temperature of 1120 for 5 hours. Results showed that the SP sample became self-glazed after firing. Adding 20% paper pulp by 1.4 ⁄ density in volume to porcelain body slip (1.36 g cellulose fiber in 100 g SP) slightly increased transmission of light. Microstructure analysis showed a large amount of glass phase, which improved translucency of the bodies. Moreover, mullite needle shaped crystals were formed via reaction of clay and molten flux due to low melt viscosity. XRD results clearly showed that the fired soft-paste porcelain contained quartz, mullite, anorthite and albite in the fired state.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47095541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amirhosein Paryab, S. Abdollahi, Rashid Khalilifard, H. M. Hosseini
As an alternative to conventional fertilizers, e.g. NPK (the Nitrogen-Phosphorous-Potassium-containing chemical fertilizers) which release their nutrients in a short time glass fertilizers are ideal as they release macroand micronutrients for crops and plant nourishment more gradually. Also, despite conventional ones, they have no ground-water pollution. In the present study, glass fertilizers were synthesized via polymer-derived ceramics (PDC) method. Despite the melt-casting procedure, PDC needs lower temperatures in heat treatment. The precursors consist of poly-siloxane and active fillers. Thus, thanks to gaseous release during heat treatment of the present active fillers, i.e. Ca(OH)2, MgCO3, and Al(OH)3, a porous microstructure can be generated. In order to manipulate the pore size and specific surface area, fractions of calcined active fillers were used. The experiments showed that upon the increase of non-calcined active fillers, the specific surface area and the amount of porosity were increased due to more gaseous release during heat treatment. Thus, affected by microstructure, the release rate of macro and micro-elements was higher in the sample containing non-calcined active fillers, in comparison to other samples. Additionally, the porous samples were able to be loaded by extra nutrients containing Nitrogen, like KNO3.
{"title":"Porous Slow Release Silicate-Phosphate Glasses Synthesized By Polymer-Derived Ceramics Method Appropriate For Plants Nourishment","authors":"Amirhosein Paryab, S. Abdollahi, Rashid Khalilifard, H. M. Hosseini","doi":"10.22068/IJMSE.18.1.9","DOIUrl":"https://doi.org/10.22068/IJMSE.18.1.9","url":null,"abstract":"As an alternative to conventional fertilizers, e.g. NPK (the Nitrogen-Phosphorous-Potassium-containing chemical fertilizers) which release their nutrients in a short time glass fertilizers are ideal as they release macroand micronutrients for crops and plant nourishment more gradually. Also, despite conventional ones, they have no ground-water pollution. In the present study, glass fertilizers were synthesized via polymer-derived ceramics (PDC) method. Despite the melt-casting procedure, PDC needs lower temperatures in heat treatment. The precursors consist of poly-siloxane and active fillers. Thus, thanks to gaseous release during heat treatment of the present active fillers, i.e. Ca(OH)2, MgCO3, and Al(OH)3, a porous microstructure can be generated. In order to manipulate the pore size and specific surface area, fractions of calcined active fillers were used. The experiments showed that upon the increase of non-calcined active fillers, the specific surface area and the amount of porosity were increased due to more gaseous release during heat treatment. Thus, affected by microstructure, the release rate of macro and micro-elements was higher in the sample containing non-calcined active fillers, in comparison to other samples. Additionally, the porous samples were able to be loaded by extra nutrients containing Nitrogen, like KNO3.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41726494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonas Fernando Macedo, I. Fioravante, R. Z. Nakazato, H. A. Acciari, E. N. Codaro
As we all know, corrosion of pipelines by hydrogen sulfide is the most worrying factor in the production and transport of oil and gas. In this work the corrosion behavior of API 5L X70MS and X70MO low carbon steels in hydrogen sulfide environment was investigated. Hydrogen induced cracking and sulfide stress cracking tests were carried out according to NACE TM0177 standard. After testing, blisters and cracks were observed only in X70MO steel, probably due to its lower grain refinement and banded microstructure. Internal cracks seem to be initiated in the elongated MnS inclusions. Corrosion process was studied by obtaining potentiodynamic polarization curves, which were registered after open circuit potential measurements, at room temperature. Both steels showed general corrosion in NACE 177A solutions, but the corrosion rate values in H2S-saturated solution were about an order of magnitude higher than the ones in deaerated solution. Hydrogen permeation was characterized in accordance with ASTM G148 standard. In deaerated H2SO4 solution, permeation measurements were similar for both steels. In H2S-saturated solution, X70 MO exhibited higher hydrogen oxidation current values than X70 MS. H2S seems to promote the reduction of protons and increase the concentration of hydrogen atoms in the solution/steel interface, favoring the diffusion process. As X70MO has a coarse microstructure, it offers more pathways for hydrogen diffusion.
{"title":"Corrosion Behavior of API 5L X70 Carbon Steels in Hydrogen Sulfide Environments","authors":"Jonas Fernando Macedo, I. Fioravante, R. Z. Nakazato, H. A. Acciari, E. N. Codaro","doi":"10.22068/IJMSE.18.1.12","DOIUrl":"https://doi.org/10.22068/IJMSE.18.1.12","url":null,"abstract":"As we all know, corrosion of pipelines by hydrogen sulfide is the most worrying factor in the production and transport of oil and gas. In this work the corrosion behavior of API 5L X70MS and X70MO low carbon steels in hydrogen sulfide environment was investigated. Hydrogen induced cracking and sulfide stress cracking tests were carried out according to NACE TM0177 standard. After testing, blisters and cracks were observed only in X70MO steel, probably due to its lower grain refinement and banded microstructure. Internal cracks seem to be initiated in the elongated MnS inclusions. Corrosion process was studied by obtaining potentiodynamic polarization curves, which were registered after open circuit potential measurements, at room temperature. Both steels showed general corrosion in NACE 177A solutions, but the corrosion rate values in H2S-saturated solution were about an order of magnitude higher than the ones in deaerated solution. Hydrogen permeation was characterized in accordance with ASTM G148 standard. In deaerated H2SO4 solution, permeation measurements were similar for both steels. In H2S-saturated solution, X70 MO exhibited higher hydrogen oxidation current values than X70 MS. H2S seems to promote the reduction of protons and increase the concentration of hydrogen atoms in the solution/steel interface, favoring the diffusion process. As X70MO has a coarse microstructure, it offers more pathways for hydrogen diffusion.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46853180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reza Soleimani Gilakjani, S. Razavi, M. Seifollahi
Niobium is a significant addition to superalloys to enhance high-temperature mechanical properties. The purpose of this study is twofold: (1) to investigate the η and γ/ phase precipitations along with (2) to identify the high-temperature tensile properties in A286 and Nb-A286, as a modified type. The heat treatment of both alloys was carried out in a two-stage aging procedure at 760 °C for 16 h and 820 °C for 2 to 30 hours, then characterized by optical and scanning electron (SEM-EDS) microscopies, differential thermal analysis (DTA), and high-temperature tensile tests. The results showed that niobium addition increased the volume fraction of γ/ phase, from 10.7 % to 12 %, decreased its size, from 94 to 71 nm, and intensified the γ/-dissolution temperature from 987 °C to 1007 °C. Moreover, the γ/ to η phase transformation was sluggishly occurred in Nb-A286 due to the higher stability of γ/ precipitations. Furthermore, the Nb-A286 alloy demonstrates higher mechanical properties than the A286 one, approximately 100 MPa improvement, which was contributed to the much larger volume fraction and finer size of more stabilized γ/ phase.
{"title":"The Effect of Niobium Addition on the Microstructure and Tensile Properties of Iron-Nickel Base A286 Superalloy","authors":"Reza Soleimani Gilakjani, S. Razavi, M. Seifollahi","doi":"10.22068/IJMSE.18.1.7","DOIUrl":"https://doi.org/10.22068/IJMSE.18.1.7","url":null,"abstract":"Niobium is a significant addition to superalloys to enhance high-temperature mechanical properties. The purpose of this study is twofold: (1) to investigate the η and γ/ phase precipitations along with (2) to identify the high-temperature tensile properties in A286 and Nb-A286, as a modified type. The heat treatment of both alloys was carried out in a two-stage aging procedure at 760 °C for 16 h and 820 °C for 2 to 30 hours, then characterized by optical and scanning electron (SEM-EDS) microscopies, differential thermal analysis (DTA), and high-temperature tensile tests. The results showed that niobium addition increased the volume fraction of γ/ phase, from 10.7 % to 12 %, decreased its size, from 94 to 71 nm, and intensified the γ/-dissolution temperature from 987 °C to 1007 °C. Moreover, the γ/ to η phase transformation was sluggishly occurred in Nb-A286 due to the higher stability of γ/ precipitations. Furthermore, the Nb-A286 alloy demonstrates higher mechanical properties than the A286 one, approximately 100 MPa improvement, which was contributed to the much larger volume fraction and finer size of more stabilized γ/ phase.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42464775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Study on the Post-annealing Process of Nb-Hf Alloy Produced by Spark Plasma Sintering","authors":"S. R. Motlagh, H. Momeni, N. Ehsani","doi":"10.22068/IJMSE.18.1.11","DOIUrl":"https://doi.org/10.22068/IJMSE.18.1.11","url":null,"abstract":"","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44278108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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