Pub Date : 2003-12-01DOI: 10.2320/MATERTRANS.44.2594
C. Uyeda, Kenta Tanaka, R. Takashima, M. Sakakibara
The effect of temperature is discussed on the magnetic-alignment process of micron-sized particles dispersed in a fluid medium, based on the experimental data compiled on various non-ferromagnetic materials having different concentrations of paramagnetic impurity ion. The field-intensity required to achieve alignment decreased with temperature following the relation calculated from the Langevin theory, when the diamagnetic particles were free of paramagnetic ions. The rotational Brownian motion was considered to randomize the direction of the microcrystals in the theory. The above-mentioned temperature dependence was expected to occur for most of the diamagnetic oxides, since the oxides were expected to possess a finite amount of diamagnetic anisotropy according to a model proposed recently to explain the origin of anisotropy. The decease of temperature caused additional reduction on the field-intensity to achieve alignment, when a finite amount of paramagnetic ion was contained in the particle. This was because the paramagnetic anisotropy increased which the reduction of temperature. The doping of paramagnetic ion on non-ferromagnetic materials in the course of processing a material expected to reduce the field intensity to achieve magnetic alignment at room temperature. The above findings, concerned with the reduction of field intensity to achieve magnetic alignment, may increase the possibility of practical applications of the phenomena of magnetic alignment.
{"title":"Characteristics of paramagnetic and diamagnetic anisotropy which induce magnetic alignment of micron-sized non-ferromagnetic particles : Structural and functional control of materials through solid-solid phase transformations in high magnetic field","authors":"C. Uyeda, Kenta Tanaka, R. Takashima, M. Sakakibara","doi":"10.2320/MATERTRANS.44.2594","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.2594","url":null,"abstract":"The effect of temperature is discussed on the magnetic-alignment process of micron-sized particles dispersed in a fluid medium, based on the experimental data compiled on various non-ferromagnetic materials having different concentrations of paramagnetic impurity ion. The field-intensity required to achieve alignment decreased with temperature following the relation calculated from the Langevin theory, when the diamagnetic particles were free of paramagnetic ions. The rotational Brownian motion was considered to randomize the direction of the microcrystals in the theory. The above-mentioned temperature dependence was expected to occur for most of the diamagnetic oxides, since the oxides were expected to possess a finite amount of diamagnetic anisotropy according to a model proposed recently to explain the origin of anisotropy. The decease of temperature caused additional reduction on the field-intensity to achieve alignment, when a finite amount of paramagnetic ion was contained in the particle. This was because the paramagnetic anisotropy increased which the reduction of temperature. The doping of paramagnetic ion on non-ferromagnetic materials in the course of processing a material expected to reduce the field intensity to achieve magnetic alignment at room temperature. The above findings, concerned with the reduction of field intensity to achieve magnetic alignment, may increase the possibility of practical applications of the phenomena of magnetic alignment.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"63 1","pages":"2594-2598"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83439538","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}
Pub Date : 2003-12-01DOI: 10.2320/matertrans.44.2701
M. Maeda, O. Igarashi, T. Shibayanagi, M. Naka
This paper describes the relation between the interfacial microstructure and the fracture strength of the joints of silicon nitride (Si 3 N 4 ) and vanadium (V) formed by solid state diffusion bonding. At first, the interfacial microstructure and its evolution process were analyzed in detail. The phase sequence at the interface changes with the bonding time showing five typical stages. In the first stage, a V 3 Si layer and V 2 N grains are formed. The V 2 N grains contact with the V 3 Si layer at 1473 K and below, while the contact is prohibited at 1498 K and above. The Si 3 N 4 /V 3 Si interface is metastable. In the second stage, a V 5 Si 3 N 1-X layer appears. In the third stage, V is annihilated. In the fourth stage, the V 3 Si layer is annihilated and VN grains are formed. In the fifth stage, V 2 N is annihilated. This evolution process of the interfacial microstructure agrees well with the proposed chemical potential diagram, except the metastable state of the interface. The increase and decrease behavior in the thickness of each reaction product interact with each other. The behavior of the V 3 Si layer is affected not only by the formation and growth of the V 5 Si 3 N 1-X layer but also by the formation of a V(Si) zone at the V 3 Si/V interface. The formation of the V 5 Si 3 N 1-X layer starts when the spatial gradient of the chemical potential of vanadium in the V 3 Si layer decreases to a certain value. The fracture strength of the joints changes depending on the bonding temperature and time. The higher bonding temperature leads to the higher maximum fracture strength. The maximum strength at each bonding temperature is achieved when the thickness of the V 3 Si layer is 2.0μm. The prolonged bonding time gradually reduces the fracture strength down to 42 MPa.
{"title":"Solid state diffusion bonding of silicon nitride using vanadium foils : Structural and functional control of materials through solid-solid phase transformations in high magnetic field","authors":"M. Maeda, O. Igarashi, T. Shibayanagi, M. Naka","doi":"10.2320/matertrans.44.2701","DOIUrl":"https://doi.org/10.2320/matertrans.44.2701","url":null,"abstract":"This paper describes the relation between the interfacial microstructure and the fracture strength of the joints of silicon nitride (Si 3 N 4 ) and vanadium (V) formed by solid state diffusion bonding. At first, the interfacial microstructure and its evolution process were analyzed in detail. The phase sequence at the interface changes with the bonding time showing five typical stages. In the first stage, a V 3 Si layer and V 2 N grains are formed. The V 2 N grains contact with the V 3 Si layer at 1473 K and below, while the contact is prohibited at 1498 K and above. The Si 3 N 4 /V 3 Si interface is metastable. In the second stage, a V 5 Si 3 N 1-X layer appears. In the third stage, V is annihilated. In the fourth stage, the V 3 Si layer is annihilated and VN grains are formed. In the fifth stage, V 2 N is annihilated. This evolution process of the interfacial microstructure agrees well with the proposed chemical potential diagram, except the metastable state of the interface. The increase and decrease behavior in the thickness of each reaction product interact with each other. The behavior of the V 3 Si layer is affected not only by the formation and growth of the V 5 Si 3 N 1-X layer but also by the formation of a V(Si) zone at the V 3 Si/V interface. The formation of the V 5 Si 3 N 1-X layer starts when the spatial gradient of the chemical potential of vanadium in the V 3 Si layer decreases to a certain value. The fracture strength of the joints changes depending on the bonding temperature and time. The higher bonding temperature leads to the higher maximum fracture strength. The maximum strength at each bonding temperature is achieved when the thickness of the V 3 Si layer is 2.0μm. The prolonged bonding time gradually reduces the fracture strength down to 42 MPa.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"113 1","pages":"2701-2710"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75971589","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}
Pub Date : 2003-12-01DOI: 10.2320/MATERTRANS.44.2427
Gjergj Dodbiba, A. Shibayama, J. Sadaki, T. Fujita
This paper examines separation of waste plastics obtained from automotive shredder operations. Thus, a mixture of three kinds of plastic components (i.e. acrylonitrile-butadiene-styrene (ABS), polypropylene (PP), and polyvinyl chloride (PVC)) is sorted by using dry techniques i.e. without using water and hazardous chemicals. The separation process is characterized by the utilization of properties of triboelectric charge and density. Considering the relative position in triboelectric series (TES) and density of the each plastic component of the ABS, PP and PVC mixture, it is concluded that a satisfactory separation could not be obtained by either triboelectrostatic separation or air tabling alone. Thus, a system utilizing a combination of the two processes is developed. The triboelectrostatic separator is initially used to collect the ABS flakes as positively charged fraction and to produce a negatively charged fraction of PP and PVC flakes for further treatment on air table. Hence, at the end of the process, products of ABS, PP and PVC with a grade of 94.3%, 92.5% and 93.7% respectively are collected with a percentage mass distribution higher than 76.7% for all of them.
{"title":"Combination of triboelectrostatic separation and air tabling for sorting plastics from a multi-component plastic mixture : New systems and processes in recycling and high performance waste treatments","authors":"Gjergj Dodbiba, A. Shibayama, J. Sadaki, T. Fujita","doi":"10.2320/MATERTRANS.44.2427","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.2427","url":null,"abstract":"This paper examines separation of waste plastics obtained from automotive shredder operations. Thus, a mixture of three kinds of plastic components (i.e. acrylonitrile-butadiene-styrene (ABS), polypropylene (PP), and polyvinyl chloride (PVC)) is sorted by using dry techniques i.e. without using water and hazardous chemicals. The separation process is characterized by the utilization of properties of triboelectric charge and density. Considering the relative position in triboelectric series (TES) and density of the each plastic component of the ABS, PP and PVC mixture, it is concluded that a satisfactory separation could not be obtained by either triboelectrostatic separation or air tabling alone. Thus, a system utilizing a combination of the two processes is developed. The triboelectrostatic separator is initially used to collect the ABS flakes as positively charged fraction and to produce a negatively charged fraction of PP and PVC flakes for further treatment on air table. Hence, at the end of the process, products of ABS, PP and PVC with a grade of 94.3%, 92.5% and 93.7% respectively are collected with a percentage mass distribution higher than 76.7% for all of them.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"87 1","pages":"2427-2435"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85207440","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}
Pub Date : 2003-10-16DOI: 10.2320/MATERTRANS.44.2452
K. Yamaguchi,, Y. Takeda
A new technique for removal of tramp-elements from steel scrap is required for saving energy and protecting the environment. An extraction method using phase separation in a liquid Fe-Pb-C system was investigated at 1453 K to obtain fundamental information on removal of copper, tin and zinc from molten iron. A mixture of iron, lead and carbon melted in a carbon crucible separates into two phases of lead and iron containing carbon. The compositions on the miscibility gap in the Fe-Pb-C system are 95.4mass% Fe-4.5 mass% C-0.1 mass% Pb and 99.9mass% Pb-0.1 mass% Fe. Distribution ratios of copper, tin and zinc between the lead and the iron phases, L X =[mass%X in molten Pb]/ (mass%X in molten Fe), are 2.2, 2.2 and 1.4, respectively. By adding a same amount of lead to an iron scrap, 70% of copper and tin from the iron scrap can be eliminated. Gold, silver and palladium are enriched in the lead rich phase. However, platinum and rhodium are more distributed to the iron rich phase than to the lead phase.
{"title":"Impurity removal from carbon saturated liquid iron using lead solvent : New systems and processes in recycling and high performance waste treatments","authors":"K. Yamaguchi,, Y. Takeda","doi":"10.2320/MATERTRANS.44.2452","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.2452","url":null,"abstract":"A new technique for removal of tramp-elements from steel scrap is required for saving energy and protecting the environment. An extraction method using phase separation in a liquid Fe-Pb-C system was investigated at 1453 K to obtain fundamental information on removal of copper, tin and zinc from molten iron. A mixture of iron, lead and carbon melted in a carbon crucible separates into two phases of lead and iron containing carbon. The compositions on the miscibility gap in the Fe-Pb-C system are 95.4mass% Fe-4.5 mass% C-0.1 mass% Pb and 99.9mass% Pb-0.1 mass% Fe. Distribution ratios of copper, tin and zinc between the lead and the iron phases, L X =[mass%X in molten Pb]/ (mass%X in molten Fe), are 2.2, 2.2 and 1.4, respectively. By adding a same amount of lead to an iron scrap, 70% of copper and tin from the iron scrap can be eliminated. Gold, silver and palladium are enriched in the lead rich phase. However, platinum and rhodium are more distributed to the iron rich phase than to the lead phase.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"3 1","pages":"2452-2455"},"PeriodicalIF":0.0,"publicationDate":"2003-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88744976","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}
Pub Date : 2003-04-01DOI: 10.2320/MATERTRANS.44.539
S. Ono, Hideo Kijima, N. Masuko
Formation behavior of anodic oxide films on magnesium in various electrolytes including fluoride was investigated with attention to the effects of anodizing voltage, pH and aluminum content. In the range of formation voltage between 2V and 100V, porous film was formed in alkaline fluoride solution associated with high current density at around 5 V and at breakdown voltage. The critical voltage of breakdown to allow maximum current flow was approximately 60V and relatively independent on substrate purity. Barrier type films or semi-barrier type films, which were composed of hydrated outer layer and inner layer, were formed at the other voltages. A peculiar phenomenon of high current density at around 5 V, which may be caused by trans-passive state, was not observed for anodizing in acidic fluoride solutions such as Dow 17 and ammonium fluoride. In the case of AZ91D, the critical voltage increased to 70 V and peculiar phenomenon at 5 V was not observed, so that only barrier films were formed at less than the critical breakdown voltage. When AlO - 2 ion was added in the electrolytes, the critical voltage remarkably increased and current density effectively decreased with increasing AlO - 2 content. The passivation effect of aluminum addition in the electrolytes is more remarkable than the addition in magnesium substrates. The depth profiles of constituent elements showed that aluminum migrated into oxide film to reach near oxide/substrate interface. Atomic ratio of aluminum to magnesium increased with increasing voltage to attain 0.42 at 80 V and crystalline MgAl 2 O 4 and MgO were found in the film.
{"title":"Microstructure and voltage-current characteristics of anodic films formed on magnesium in electrolytes containing fluoride : Special issue on platform science and technology for advanced magnesium alloys, II","authors":"S. Ono, Hideo Kijima, N. Masuko","doi":"10.2320/MATERTRANS.44.539","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.539","url":null,"abstract":"Formation behavior of anodic oxide films on magnesium in various electrolytes including fluoride was investigated with attention to the effects of anodizing voltage, pH and aluminum content. In the range of formation voltage between 2V and 100V, porous film was formed in alkaline fluoride solution associated with high current density at around 5 V and at breakdown voltage. The critical voltage of breakdown to allow maximum current flow was approximately 60V and relatively independent on substrate purity. Barrier type films or semi-barrier type films, which were composed of hydrated outer layer and inner layer, were formed at the other voltages. A peculiar phenomenon of high current density at around 5 V, which may be caused by trans-passive state, was not observed for anodizing in acidic fluoride solutions such as Dow 17 and ammonium fluoride. In the case of AZ91D, the critical voltage increased to 70 V and peculiar phenomenon at 5 V was not observed, so that only barrier films were formed at less than the critical breakdown voltage. When AlO - 2 ion was added in the electrolytes, the critical voltage remarkably increased and current density effectively decreased with increasing AlO - 2 content. The passivation effect of aluminum addition in the electrolytes is more remarkable than the addition in magnesium substrates. The depth profiles of constituent elements showed that aluminum migrated into oxide film to reach near oxide/substrate interface. Atomic ratio of aluminum to magnesium increased with increasing voltage to attain 0.42 at 80 V and crystalline MgAl 2 O 4 and MgO were found in the film.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"101 3","pages":"539-545"},"PeriodicalIF":0.0,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91471742","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}
Pub Date : 2003-04-01DOI: 10.2320/MATERTRANS.44.511
A. Yamamoto, H. Tsubakino
A new technique has been proposed for improving the poor corrosion resistance in magnesium and its alloys. The specimens were immersed into solutions with high pH values, such as 10% NaOH, (1% NaCl + 10% NaOH) and (10% NaCI + 10% NaOH) solutions, at R. T. for 3.6 ks, and then heat treated in air at 673-773 K for 3.6 ks. Corrosion resistance of the specimens were evaluated by the time for occurring filiform corrosion, t f , in salt immersion test using 1% NaCl solution. Hydrogen bubble evolution at the early stage of the salt immersion test was suppressed by the corrosion-oxidization treatment, and also t f was prolonged by this treatment. On the non-treated specimen of AZ31 alloy, t f was about 1.7 ks, and on the specimen only heat-treated in air at 673 K without the primary immersion, t f was about 1.9 ks. On the other hand, when the (10% NaCI + 10% NaOH) solution was used for the primary immersion and then heated in air at 673 K for 3.6 ks, t f was prolonged up to about 35 ks, about 20 times longer than that in the non-treated specimen. It is considered that magnesium hydroxide formed on the surface of the specimen by the primary immersion treatment changed into magnesium oxide which protected the specimen from corrosion. Formation of magnesium oxide on both the surfaces of the specimens treated by the corrosion-oxidization method and heated without the primary immersion was confirmed by TEM observations. Microstructures in both the oxide layers were different one another, cohesion of the oxide formed directly from metallic magnesium seemed to be weak compared with that formed from magnesium hydroxide.
{"title":"Surface treatment of magnesium alloys by artificial corrosion-oxidization method : Special issue on platform science and technology for advanced magnesium alloys, II","authors":"A. Yamamoto, H. Tsubakino","doi":"10.2320/MATERTRANS.44.511","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.511","url":null,"abstract":"A new technique has been proposed for improving the poor corrosion resistance in magnesium and its alloys. The specimens were immersed into solutions with high pH values, such as 10% NaOH, (1% NaCl + 10% NaOH) and (10% NaCI + 10% NaOH) solutions, at R. T. for 3.6 ks, and then heat treated in air at 673-773 K for 3.6 ks. Corrosion resistance of the specimens were evaluated by the time for occurring filiform corrosion, t f , in salt immersion test using 1% NaCl solution. Hydrogen bubble evolution at the early stage of the salt immersion test was suppressed by the corrosion-oxidization treatment, and also t f was prolonged by this treatment. On the non-treated specimen of AZ31 alloy, t f was about 1.7 ks, and on the specimen only heat-treated in air at 673 K without the primary immersion, t f was about 1.9 ks. On the other hand, when the (10% NaCI + 10% NaOH) solution was used for the primary immersion and then heated in air at 673 K for 3.6 ks, t f was prolonged up to about 35 ks, about 20 times longer than that in the non-treated specimen. It is considered that magnesium hydroxide formed on the surface of the specimen by the primary immersion treatment changed into magnesium oxide which protected the specimen from corrosion. Formation of magnesium oxide on both the surfaces of the specimens treated by the corrosion-oxidization method and heated without the primary immersion was confirmed by TEM observations. Microstructures in both the oxide layers were different one another, cohesion of the oxide formed directly from metallic magnesium seemed to be weak compared with that formed from magnesium hydroxide.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"7 1","pages":"511-517"},"PeriodicalIF":0.0,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89658812","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}
Pub Date : 2003-01-01DOI: 10.2320/MATERTRANS.44.34
Y. Nose, T. Ikeda, H. Nakajima, H. Numakura
The tracer diffusion coefficient of Fe and the chemical diffusion coefficient in L1 2 -ordered Pt 3 Fe have been measured at temperatures below the order-disorder transition temperature. The tracer diffusion coefficient of Fe in a nearly stoichiometric alloy is curved upwards in the Arrhenius plot on approaching the order-disorder transition temperature. The chemical diffusion coefficient is about 10-30 times larger than the diffusion coefficient of Fe. The tracer diffusion coefficient is influenced by composition, namely, it increases with increasing the concentration of Fe through the stoichiometric composition, but this trend almost vanishes at higher temperatures. The chemical diffusion coefficient is virtually independent of composition. The tracer diffusion coefficient of Pt has been estimated from the Darken-Manning relation. At 1223 K, it is in between the chemical diffusion coefficient and the tracer diffusion coefficient of Fe.
{"title":"Tracer and chemical diffusion in L12-Ordered Pt3Fe : Diffusion in materials and its application: Recent development","authors":"Y. Nose, T. Ikeda, H. Nakajima, H. Numakura","doi":"10.2320/MATERTRANS.44.34","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.34","url":null,"abstract":"The tracer diffusion coefficient of Fe and the chemical diffusion coefficient in L1 2 -ordered Pt 3 Fe have been measured at temperatures below the order-disorder transition temperature. The tracer diffusion coefficient of Fe in a nearly stoichiometric alloy is curved upwards in the Arrhenius plot on approaching the order-disorder transition temperature. The chemical diffusion coefficient is about 10-30 times larger than the diffusion coefficient of Fe. The tracer diffusion coefficient is influenced by composition, namely, it increases with increasing the concentration of Fe through the stoichiometric composition, but this trend almost vanishes at higher temperatures. The chemical diffusion coefficient is virtually independent of composition. The tracer diffusion coefficient of Pt has been estimated from the Darken-Manning relation. At 1223 K, it is in between the chemical diffusion coefficient and the tracer diffusion coefficient of Fe.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"92 1","pages":"34-39"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76731507","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}
Pub Date : 2003-01-01DOI: 10.2320/MATERTRANS.44.47
T. Ogata, M. Akabori, A. Itoh
Two types of diffusion couples, U-23 mol%Zr with U-23 mot%Zr-1.3 mol%Ce and U-95 mol%Zr with U-23 mol%Zr-1.3 mol%Ce, were annealed isothermally at 1123 K and 1023 K in order to provide basic data on Ce diffusion in U-Zr alloys, which are the fuel forms for advanced nuclear reactors. Because the Ce solubility in the U-23 mol%Zr alloy is less than I mol% in this temperature range, Ce-rich precipitates were formed and dispersed in the U-23mol%Zr-1.3mol%Ce alloy. The concentration profiles of Ce in the U-23mol%Zr/U-23mol%Zr-1.3 mol%Ce couples were analyzed based on the theoretical solutions of the one-dimensional diffusion equation for the semi-infinite diffusion couple, either side of which is supersaturated with the diffusing substance. From this analysis, the diffusion coefficients of Ce in the U-23 mol%Zr solid solution (y-U, β-Zr) were estimated to be ∼2 x 10 -13 m 2 /s at 1123K and ∼6 x 10 -14 m 2 /s at 1023 K, which are between the values extrapolated from the reported self-diffusion coefficients of γ-U and β-Zr. In the U-95 mol%Zr/U-23 mot%Zr-1.3 mol%Ce couples annealed at 1123 K and 1023 K, the concentration profiles showed up-hill diffusion of Ce. The interdiffusion coefficients in this quasi-binary U-Zr system containing Ce were obtained from the U or Zr concentration profile and compared with the reported interdiffusion coefficients in the binary U-Zr system without Ce. The result indicated that Ce does not have significant influence on interdiffusion in the U-Zr solid solutions.
{"title":"Diffusion of cerium in uranium-zirconium solid solutions : Diffusion in materials and its application: Recent development","authors":"T. Ogata, M. Akabori, A. Itoh","doi":"10.2320/MATERTRANS.44.47","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.47","url":null,"abstract":"Two types of diffusion couples, U-23 mol%Zr with U-23 mot%Zr-1.3 mol%Ce and U-95 mol%Zr with U-23 mol%Zr-1.3 mol%Ce, were annealed isothermally at 1123 K and 1023 K in order to provide basic data on Ce diffusion in U-Zr alloys, which are the fuel forms for advanced nuclear reactors. Because the Ce solubility in the U-23 mol%Zr alloy is less than I mol% in this temperature range, Ce-rich precipitates were formed and dispersed in the U-23mol%Zr-1.3mol%Ce alloy. The concentration profiles of Ce in the U-23mol%Zr/U-23mol%Zr-1.3 mol%Ce couples were analyzed based on the theoretical solutions of the one-dimensional diffusion equation for the semi-infinite diffusion couple, either side of which is supersaturated with the diffusing substance. From this analysis, the diffusion coefficients of Ce in the U-23 mol%Zr solid solution (y-U, β-Zr) were estimated to be ∼2 x 10 -13 m 2 /s at 1123K and ∼6 x 10 -14 m 2 /s at 1023 K, which are between the values extrapolated from the reported self-diffusion coefficients of γ-U and β-Zr. In the U-95 mol%Zr/U-23 mot%Zr-1.3 mol%Ce couples annealed at 1123 K and 1023 K, the concentration profiles showed up-hill diffusion of Ce. The interdiffusion coefficients in this quasi-binary U-Zr system containing Ce were obtained from the U or Zr concentration profile and compared with the reported interdiffusion coefficients in the binary U-Zr system without Ce. The result indicated that Ce does not have significant influence on interdiffusion in the U-Zr solid solutions.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"28 1","pages":"47-52"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78114280","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}
Pub Date : 2003-01-01DOI: 10.2320/MATERTRANS.44.78
R. Nakamura, Y. Yamazaki, Y. Iijima
Interdiffusion coefficient in the B2 FeAl phase at 46-50 at%Al has been measured in the temperature range from 1173 to 1473 K under the pressure from 0.1 MPa to 5GPa, The activation volume for interdiffusion, ΔV, derived from the pressure dependence of interdiffusion coefficient is found to be 0.58-0.90V m (V m : molar volume of alloys), which is comparable to or larger than 0.4-0.6V m for the monovacancy mechanism in bcc pure metals or random alloys. The value of AV increases with increasing temperature and also with deviating from stoichiometry, suggesting that divacancy contributes to the diffusion in higher temperatures and in the region of off-stoichiometry.
相互扩散系数在B2•菲尔阶段在46-50 %艾尔已经测量温度范围从1173到1473 K 5平均绩点在0.1 MPa的压力下,相互扩散的激活体积,ΔV,来自相互扩散系数对压力的依赖关系被发现是0.58 - -0.90 V m (V m:摩尔体积的合金),相当于或大于0.4 - -0.6 V m bcc monovacancy机制的随机纯金属或合金。AV值随温度升高和偏离化学计量而增加，表明距离有助于在较高温度和非化学计量区域的扩散。
{"title":"Interdiffusion in B2 type intermetallic compound FeAl under high pressures : Diffusion in materials and its application: Recent development","authors":"R. Nakamura, Y. Yamazaki, Y. Iijima","doi":"10.2320/MATERTRANS.44.78","DOIUrl":"https://doi.org/10.2320/MATERTRANS.44.78","url":null,"abstract":"Interdiffusion coefficient in the B2 FeAl phase at 46-50 at%Al has been measured in the temperature range from 1173 to 1473 K under the pressure from 0.1 MPa to 5GPa, The activation volume for interdiffusion, ΔV, derived from the pressure dependence of interdiffusion coefficient is found to be 0.58-0.90V m (V m : molar volume of alloys), which is comparable to or larger than 0.4-0.6V m for the monovacancy mechanism in bcc pure metals or random alloys. The value of AV increases with increasing temperature and also with deviating from stoichiometry, suggesting that divacancy contributes to the diffusion in higher temperatures and in the region of off-stoichiometry.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"8 1","pages":"78-82"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81798272","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}
Pub Date : 2002-12-01DOI: 10.2320/MATERTRANS.43.2949
Y. Okazaki, E. Gotoh
The corrosion fatigue properties under sine wave loading in Eagle's medium were compared among various metallic biomaterials: SUS-316L stainless steel, Co-Cr-Mo cast alloy and three types of vanadium-free titanium alloy, namely a + β type Ti-6Al-7Nb, Ti-6Al-2Nb-1Ta and a variety of newly developed Ti-15Zr-4Ta-4Nb alloys. The number of cycles to failure for the SUS-316L stainless steel and Co-Cr-Mo cast alloy increased as the maximum stress decreased. The fatigue strengths of the SUS-316L stainless steel and Co-Cr-Mo cast alloy at 1 × 10 8 cycles were much lower than those of the titanium alloys. The fatigue strengths of the vanadium-free Ti-6Al-7Nb and Ti-6Al-2Nb-1Ta alloys at 1 x 10 8 cycles were approximately 600 and 720 MPa, respectively. The fatigue strengths of the Ti-15Zr-4Nb-4Ta alloys annealed at 700°C for 2 h were about 700 MPa at 1 x 10 8 cycles, and were not significantly affected by varying the frequency from 2 to 10 Hz. Aging of the Ti-15Zr-4Nb-4Ta alloy containing 0.2%O and 0.05%N after solution treatment increased its ultimate tensile strength to 1150 MPa, and the total elongation and reduction in the area were 15 and 50%, respectively. The fatigue strength of the Ti-15Zr-4Ta-4Nb alloy treated in this way was 880 MPa under sine wave loading of 10 Hz at I x 10 8 cycles. This strength proved to be nearly identical to that estimated for the human hip joint, following an analysis of its movements and the forces acting upon it in vivo. The fatigue strength ratios at 1 x 10 8 cycles to ultimate tensile strength of the SUS-316L stainless steel and Co-Cr-Mo cast alloy were about 50%. The fatigue strength ratio at I x 10 8 cycles to ultimate tensile strength of the Ti-6Al-2Nb-1Ta alloy was high at 75%. In the case of the Ti-15Zr-4Nb-4Ta alloy annealed or aged after solution treatment, the fatigue strength ratio to ultimate tensile strength was about 75%. Many striations and cracks caused by fatigue were visible on the fatigue-fractured surfaces of the SUS-316L stainless steel and Co-Cr-Mo cast alloy. Micro-cracks in dimples were also apparent on the fatigue-fractured surface of the titanium alloys.
{"title":"Corrosion fatigue properties of metallic biomaterials in Eagle's medium : Biomaterials and bioengineering","authors":"Y. Okazaki, E. Gotoh","doi":"10.2320/MATERTRANS.43.2949","DOIUrl":"https://doi.org/10.2320/MATERTRANS.43.2949","url":null,"abstract":"The corrosion fatigue properties under sine wave loading in Eagle's medium were compared among various metallic biomaterials: SUS-316L stainless steel, Co-Cr-Mo cast alloy and three types of vanadium-free titanium alloy, namely a + β type Ti-6Al-7Nb, Ti-6Al-2Nb-1Ta and a variety of newly developed Ti-15Zr-4Ta-4Nb alloys. The number of cycles to failure for the SUS-316L stainless steel and Co-Cr-Mo cast alloy increased as the maximum stress decreased. The fatigue strengths of the SUS-316L stainless steel and Co-Cr-Mo cast alloy at 1 × 10 8 cycles were much lower than those of the titanium alloys. The fatigue strengths of the vanadium-free Ti-6Al-7Nb and Ti-6Al-2Nb-1Ta alloys at 1 x 10 8 cycles were approximately 600 and 720 MPa, respectively. The fatigue strengths of the Ti-15Zr-4Nb-4Ta alloys annealed at 700°C for 2 h were about 700 MPa at 1 x 10 8 cycles, and were not significantly affected by varying the frequency from 2 to 10 Hz. Aging of the Ti-15Zr-4Nb-4Ta alloy containing 0.2%O and 0.05%N after solution treatment increased its ultimate tensile strength to 1150 MPa, and the total elongation and reduction in the area were 15 and 50%, respectively. The fatigue strength of the Ti-15Zr-4Ta-4Nb alloy treated in this way was 880 MPa under sine wave loading of 10 Hz at I x 10 8 cycles. This strength proved to be nearly identical to that estimated for the human hip joint, following an analysis of its movements and the forces acting upon it in vivo. The fatigue strength ratios at 1 x 10 8 cycles to ultimate tensile strength of the SUS-316L stainless steel and Co-Cr-Mo cast alloy were about 50%. The fatigue strength ratio at I x 10 8 cycles to ultimate tensile strength of the Ti-6Al-2Nb-1Ta alloy was high at 75%. In the case of the Ti-15Zr-4Nb-4Ta alloy annealed or aged after solution treatment, the fatigue strength ratio to ultimate tensile strength was about 75%. Many striations and cracks caused by fatigue were visible on the fatigue-fractured surfaces of the SUS-316L stainless steel and Co-Cr-Mo cast alloy. Micro-cracks in dimples were also apparent on the fatigue-fractured surface of the titanium alloys.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"64 1","pages":"2949-2955"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90319646","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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