Pub Date : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1303
B. Kim, D. Suhr
The objective of this study was to investigate the characteristics of fine-Al 2 O 3 coating after plasma spraying using fine-Al 2 O 3 powder which has the particle size distribution of 1-12 μm and the mean particle size of 4.12 μm. The microstructure of the coating was very dense and the width of each splat of the fine alumina powder was approximately 10 μm. The average thickness of splats was approximately 1.4 μm, and this value was approximately 1/3 of mean particle size. The surface roughness of the coating was Ra = 5.2 μm and this result was approximately 30% lower than the surface roughness of other plasma-sprayed Al 2 O 3 coatings. The main phase of the coating was γ-Al 2 O 3 and also a little of α-Al 2 O 3 phase was observed. The fraction of α-Al 2 O 3 in the coating was 8.39%. Micro-hardness ranged from 1030 to 890 depending on the indentation load and differed little from commercial Al 2 O 3 coating but the hardness variation was relatively large. Nonetheless, it is expected that the fine-Al 2 O 3 coating will be used as coating materials because it does not require post-surface finishing after spraying.
{"title":"Characteristics of plasma-sprayed coatings using fine Al2O3 powder","authors":"B. Kim, D. Suhr","doi":"10.2320/MATERTRANS1989.41.1303","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1303","url":null,"abstract":"The objective of this study was to investigate the characteristics of fine-Al 2 O 3 coating after plasma spraying using fine-Al 2 O 3 powder which has the particle size distribution of 1-12 μm and the mean particle size of 4.12 μm. The microstructure of the coating was very dense and the width of each splat of the fine alumina powder was approximately 10 μm. The average thickness of splats was approximately 1.4 μm, and this value was approximately 1/3 of mean particle size. The surface roughness of the coating was Ra = 5.2 μm and this result was approximately 30% lower than the surface roughness of other plasma-sprayed Al 2 O 3 coatings. The main phase of the coating was γ-Al 2 O 3 and also a little of α-Al 2 O 3 phase was observed. The fraction of α-Al 2 O 3 in the coating was 8.39%. Micro-hardness ranged from 1030 to 890 depending on the indentation load and differed little from commercial Al 2 O 3 coating but the hardness variation was relatively large. Nonetheless, it is expected that the fine-Al 2 O 3 coating will be used as coating materials because it does not require post-surface finishing after spraying.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"123 1","pages":"1303-1306"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73753363","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1322
K. Yamashita, C. Watanabe, S. Kumai, M. Kato, A. Sato, Yoshimi Watanabe
An Al-Al 3 Ti composite has been prepared to contain a large volume fraction of D02 2O ordered Al 3 Ti phase on one side and a smaller volume fraction on the other side by a functional grading process. The cyclic stress-strain curves obtained by strain control tests are compared with the available data on Al to delineate the effects of the Al 3 Ti plates distributed with concentration gradient. Examination of the crack nucleation and growth by a replica method has revealed that introduction of the non-deformable Al 3 Ti accelerates crack nucleation but concurrently hinders the spontaneous propagation in the cyclic tests. Observation of the final structure by HVEM has further revealed that presence of the non-deformable Al 3 Ti induces non-uniform distribution of dislocations near the Al 3 Ti plate, causing build-up of stress inhomogeneity, especially on the Al 3 Ti rich side. On the basis of these observations, utility of the FGM specimens is discussed with a particular interest in the lifetime prediction under cyclic loading.
{"title":"Cyclic Deformation and Development of Dislocation Structures in a Centrifugally Cast Al–Al3Ti of Functionally Graded Material","authors":"K. Yamashita, C. Watanabe, S. Kumai, M. Kato, A. Sato, Yoshimi Watanabe","doi":"10.2320/MATERTRANS1989.41.1322","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1322","url":null,"abstract":"An Al-Al 3 Ti composite has been prepared to contain a large volume fraction of D02 2O ordered Al 3 Ti phase on one side and a smaller volume fraction on the other side by a functional grading process. The cyclic stress-strain curves obtained by strain control tests are compared with the available data on Al to delineate the effects of the Al 3 Ti plates distributed with concentration gradient. Examination of the crack nucleation and growth by a replica method has revealed that introduction of the non-deformable Al 3 Ti accelerates crack nucleation but concurrently hinders the spontaneous propagation in the cyclic tests. Observation of the final structure by HVEM has further revealed that presence of the non-deformable Al 3 Ti induces non-uniform distribution of dislocations near the Al 3 Ti plate, causing build-up of stress inhomogeneity, especially on the Al 3 Ti rich side. On the basis of these observations, utility of the FGM specimens is discussed with a particular interest in the lifetime prediction under cyclic loading.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"7 1","pages":"1322-1328"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82759227","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1366
N. Yasumaru, Hiroyuki Magara, T. Ibe
Austenitic type 304 stainless steel was ion-nitrided and subsequently ion-plated with Cr-Ni-N whose Ni content was varied from 0 at% to 50at%. The ceramic film of CrN coated onto the pre-nitrided steel demonstrated good wear resistance even under a heavy load. Furthermore, a 10 μm thick CrN film exhibited the least wear among the 3 to 19 μm thick CrN films. The Cr-Ni-N films containing Ni were composed of mixed phases of Cr*N and Ni. Cr*N is a newly observed Cr nitride that may contain some Ni and has been identified as an f.c.t. structure. A Cr-Ni-N film with Ni content of 11 at% coated onto the pre-nitrided steel demonstrated the best wear resistance among the CrN film or Cr-Ni-N films with high Ni content. This superior wear resistance was maintained even at film thicknesses exceeding 20 μm, unlike the tendency of CrN film.
{"title":"Mechanical Properties of Cr–Ni–N Films Deposited on Pre-Nitrided Steels","authors":"N. Yasumaru, Hiroyuki Magara, T. Ibe","doi":"10.2320/MATERTRANS1989.41.1366","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1366","url":null,"abstract":"Austenitic type 304 stainless steel was ion-nitrided and subsequently ion-plated with Cr-Ni-N whose Ni content was varied from 0 at% to 50at%. The ceramic film of CrN coated onto the pre-nitrided steel demonstrated good wear resistance even under a heavy load. Furthermore, a 10 μm thick CrN film exhibited the least wear among the 3 to 19 μm thick CrN films. The Cr-Ni-N films containing Ni were composed of mixed phases of Cr*N and Ni. Cr*N is a newly observed Cr nitride that may contain some Ni and has been identified as an f.c.t. structure. A Cr-Ni-N film with Ni content of 11 at% coated onto the pre-nitrided steel demonstrated the best wear resistance among the CrN film or Cr-Ni-N films with high Ni content. This superior wear resistance was maintained even at film thicknesses exceeding 20 μm, unlike the tendency of CrN film.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"22 2 1","pages":"1366-1370"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86761610","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1293
Chan Liu
Boron carbide (B 4.3 C) semiconductors with metal incorporation were prepared by hot pressing mixtures of boron carbide powder (B 4.3 C) and 0.5 ∼ 1 at% metal (Zr or V). The influences of impurity incorporation on the subtle structure and conductivity of B 4.3 C crystals were investigated. Positron lifetime spectrum, x-ray diffraction and Doppler-broadening analyses indicate that appropriate metal introduction can modify the B 4.3 C structure. Especially, noticeable vacancies are introduced into about the B(3) sites at the chain centers. Meanwhile, the B 4.3 C lattice cell contracts a little along the c axis. No distinctive change of the electrical conductivity is found to accompany the structural change.
{"title":"Positron Spectroscopy of Boron Carbide Containing Metal Impurity","authors":"Chan Liu","doi":"10.2320/MATERTRANS1989.41.1293","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1293","url":null,"abstract":"Boron carbide (B 4.3 C) semiconductors with metal incorporation were prepared by hot pressing mixtures of boron carbide powder (B 4.3 C) and 0.5 ∼ 1 at% metal (Zr or V). The influences of impurity incorporation on the subtle structure and conductivity of B 4.3 C crystals were investigated. Positron lifetime spectrum, x-ray diffraction and Doppler-broadening analyses indicate that appropriate metal introduction can modify the B 4.3 C structure. Especially, noticeable vacancies are introduced into about the B(3) sites at the chain centers. Meanwhile, the B 4.3 C lattice cell contracts a little along the c axis. No distinctive change of the electrical conductivity is found to accompany the structural change.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"707 1","pages":"1293-1296"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76899189","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1351
Youichirou Ogawa, A. Kasahara, S. Iwasaki, Hiroaki Nakamura
To obtain highly ionic conductor of sulfides, a solid solution of 95CaS-5Na 2 S was prepared by sintering the powder mixture of CaS and Na 2 S which has the NaCl type structure and the anti-fluorite structure, respectively. Two concentration cells using the solid solution as solid electolyte were constructed as follows. Fe, FeS|95CaS-5Na 2 S|Mn, MnS Ag, Ag 2 S|95CaS-5Na 2 S|Cu, Cu 2 S The reversibility of the measured e.m.f. was confirmed. The electromotive forces of the concentration cells were measured over the temperature range 670 to 1120K. Because the measured values for the concentration cells were close to theoretical values calculated using the Nemst equation, it is concluded that the ionic transference number of the solid solution, 95CaS-5Na 2 S, is close to one.
为获得硫化物的高离子导体，将具有NaCl型结构和抗萤石结构的ca和na2s粉末混合物烧结制备了95cas - 5na2s固溶体。以该固溶体为固体电解质，构建了两个浓缩池。Fe, FeS|95CaS-5Na 2s |Mn, MnS Ag, Ag 2s |95CaS-5Na 2s |Cu, Cu 2s。在670 ~ 1120K的温度范围内测量了浓缩电池的电动势。由于浓度池的实测值与Nemst方程计算的理论值接近，因此得出95cas - 5na2s固溶体的离子转移数接近于1的结论。
{"title":"Ionic Transport Number of CaS–Na2S Solid Electrolytes","authors":"Youichirou Ogawa, A. Kasahara, S. Iwasaki, Hiroaki Nakamura","doi":"10.2320/MATERTRANS1989.41.1351","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1351","url":null,"abstract":"To obtain highly ionic conductor of sulfides, a solid solution of 95CaS-5Na 2 S was prepared by sintering the powder mixture of CaS and Na 2 S which has the NaCl type structure and the anti-fluorite structure, respectively. Two concentration cells using the solid solution as solid electolyte were constructed as follows. Fe, FeS|95CaS-5Na 2 S|Mn, MnS Ag, Ag 2 S|95CaS-5Na 2 S|Cu, Cu 2 S The reversibility of the measured e.m.f. was confirmed. The electromotive forces of the concentration cells were measured over the temperature range 670 to 1120K. Because the measured values for the concentration cells were close to theoretical values calculated using the Nemst equation, it is concluded that the ionic transference number of the solid solution, 95CaS-5Na 2 S, is close to one.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"14 1","pages":"1351-1355"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89706270","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1342
B.-P. Zhang, Xiao-Yong Yan, K. Shibata, T. Uda, M. Tada, M. Hirasawa
The mechanisms of reactions are investigated between polyvinyl chloride and oxides such as ZnO, Fe 2 O 3 and ZnFe 2 O 4 under inert gas atmosphere at high temperature with combined thermogravimetry-mass spectrometry (TG-MS) technique. From the experiments under a constant heating rate of 40 K/min, the following results are obtained. In the case of mixture pellet of ZnO and PVC, the chlorination of Zn in ZnO to ZnCl 2 by Cl in PVC starts at a relatively low temperature about 473 K without the formation of HCl. The chlorination is followed by the de-hydrochlorination of residual un-reacted PVC, also by the further degradation to lower order hydrocarbons, and finally by the evaporation of ZnCl 2 at higher temperature. On the other hand, in the case of ZnO-PVC double layer pellet in which ZnO layer is compacted at the top of PVC layer, PVC decomposition accompanying HCl formation starts at about 523 K, which is similar to the thermal decomposition of pure PVC in the absence of the oxide. The chlorination of Zn is not favored in this case of double layer sample. In the case of Fe 2 O 3 -PVC mixture, the de-hydrochlorination takes place at the temperature range of 513 to 673 K, similarly with the case of the pure PVC decomposition. With increasing temperature, the degradation of de-hydrochlorinated PVC residue to lower hydrocarbons and the stepwise reduction from Fe 2 O 3 to metallic Fe takes, place after the de-hydrochlorination. The reaction scheme of ZnFe 2 O 4 -PVC system shows intermediate character between ZnO-PVC system and Fe 2 O 3 -PVC system. The kinetic mechanisms of the reaction between the oxides and PVC are examined on the basis of the experimental results.
{"title":"Thermogravimetric-Mass Spectrometric Analysis of the Reactions between Oxide (ZnO, Fe 2 O 3 or ZnFe 2 O 4 ) and Polyvinyl Chloride under Inert Atmosphere","authors":"B.-P. Zhang, Xiao-Yong Yan, K. Shibata, T. Uda, M. Tada, M. Hirasawa","doi":"10.2320/MATERTRANS1989.41.1342","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1342","url":null,"abstract":"The mechanisms of reactions are investigated between polyvinyl chloride and oxides such as ZnO, Fe 2 O 3 and ZnFe 2 O 4 under inert gas atmosphere at high temperature with combined thermogravimetry-mass spectrometry (TG-MS) technique. From the experiments under a constant heating rate of 40 K/min, the following results are obtained. In the case of mixture pellet of ZnO and PVC, the chlorination of Zn in ZnO to ZnCl 2 by Cl in PVC starts at a relatively low temperature about 473 K without the formation of HCl. The chlorination is followed by the de-hydrochlorination of residual un-reacted PVC, also by the further degradation to lower order hydrocarbons, and finally by the evaporation of ZnCl 2 at higher temperature. On the other hand, in the case of ZnO-PVC double layer pellet in which ZnO layer is compacted at the top of PVC layer, PVC decomposition accompanying HCl formation starts at about 523 K, which is similar to the thermal decomposition of pure PVC in the absence of the oxide. The chlorination of Zn is not favored in this case of double layer sample. In the case of Fe 2 O 3 -PVC mixture, the de-hydrochlorination takes place at the temperature range of 513 to 673 K, similarly with the case of the pure PVC decomposition. With increasing temperature, the degradation of de-hydrochlorinated PVC residue to lower hydrocarbons and the stepwise reduction from Fe 2 O 3 to metallic Fe takes, place after the de-hydrochlorination. The reaction scheme of ZnFe 2 O 4 -PVC system shows intermediate character between ZnO-PVC system and Fe 2 O 3 -PVC system. The kinetic mechanisms of the reaction between the oxides and PVC are examined on the basis of the experimental results.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"22 1","pages":"1342-1350"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82683262","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1337
S. Chang, D. Shin, Atsushi Fukatsu, H. Tezuka, A. Kamio
The coarsening of the primary a phase in a Mg-6.0%Zn-2.0%Ca-1.5%Zr alloy in the semi-solid state temperature range was investigated to establish the necessary processing conditions for the semi solid state forming processes. The growth of the primary α phase was found to be influenced by the sample heating and holding duration. In addition, the growth rate was observed to be rather high for a lower holding temperature. These phenomena were discussed based on the experimentally measured distance between the grains in the semi-solid state.
{"title":"Growth of primary a phase in the semi-solid state Mg-Zn-Ca-Zr alloy","authors":"S. Chang, D. Shin, Atsushi Fukatsu, H. Tezuka, A. Kamio","doi":"10.2320/MATERTRANS1989.41.1337","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1337","url":null,"abstract":"The coarsening of the primary a phase in a Mg-6.0%Zn-2.0%Ca-1.5%Zr alloy in the semi-solid state temperature range was investigated to establish the necessary processing conditions for the semi solid state forming processes. The growth of the primary α phase was found to be influenced by the sample heating and holding duration. In addition, the growth rate was observed to be rather high for a lower holding temperature. These phenomena were discussed based on the experimentally measured distance between the grains in the semi-solid state.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"37 1","pages":"1337-1341"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80638656","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1275
Katsuya Matsumoto, S. Komatsu, M. Ikeda, B. Verlinden, P. Ratchev
An Al-1.0 mass%Mg 2 Si alloy was aged at 473 K for 36ks. Using the same sample, resistivity (p) measurements, tensile tests and TEM observations were carried out. The volume fraction (V fρ ) of precipitates was estimated from the decrement in resistivity due to aging. Length (λ), diameter (d) and number density (Np) per unit volume of the needle-shaped precipitates were measured on TEM micrographs. Perhaps because of initiation of overaging in the present aging condition, λ and Np showed a wide scatter and differed significantly in two equivalent samples, independently heat treated and tested. However, proof stress and V fρ in the two runs well coincided with each other and the volume fraction estimated from TEM micrographs (V fTEM ) matched within a factor of 2 for the two runs.
{"title":"Quantification of volume fraction of precipitates in an aged Al-1.0 mass%Mg2Si alloy","authors":"Katsuya Matsumoto, S. Komatsu, M. Ikeda, B. Verlinden, P. Ratchev","doi":"10.2320/MATERTRANS1989.41.1275","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1275","url":null,"abstract":"An Al-1.0 mass%Mg 2 Si alloy was aged at 473 K for 36ks. Using the same sample, resistivity (p) measurements, tensile tests and TEM observations were carried out. The volume fraction (V fρ ) of precipitates was estimated from the decrement in resistivity due to aging. Length (λ), diameter (d) and number density (Np) per unit volume of the needle-shaped precipitates were measured on TEM micrographs. Perhaps because of initiation of overaging in the present aging condition, λ and Np showed a wide scatter and differed significantly in two equivalent samples, independently heat treated and tested. However, proof stress and V fρ in the two runs well coincided with each other and the volume fraction estimated from TEM micrographs (V fTEM ) matched within a factor of 2 for the two runs.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"14 1","pages":"1275-1281"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83859799","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1307
Masarni Taguchi, T. Hirasawa
Pb-0.08 mass%Ca-Sn alloys with a wide range of Sn contents were prepared, and then immersed in 4.50kmol m -3 H 2 SO 4 at 348 K to elucidate the influence of Sn content on their corrosion behavior. Under natural immersion, the corrosion current of the Pb-Ca-Sn alloys is governed by the cathodic reaction, which involves the consumption of dissolved oxygen. The anodic reaction consists mostly of PbSO 4 formation and Sn dissolution. For the Pb-Ca-Sn alloys with 0 ∼ 0.2 mass%Sn, 99% of the anodic current is used in the former reaction. The formation of the sulfate, which is noticeably fragile and low in strength, can be assumed to be one cause for the serious corrosion damage to the low-Sn alloy grids in high-temperature sulfuric acid solution. On the other hand, the current for the PbSO 4 formation decreases linearly with increasing Sn content in the alloys at about 0.3 mass% Sn or more. For the high-Sn alloys such as Pb-0.08 mass%Ca-1.2 mass%Sn, the ratio of PbSO 4 formation to the anodic current is lowered by the Sn content, and the mechanical strength may be maintained at a high level to prevent serious corrosion.
制备了不同Sn含量的Pb-0.08质量%Ca-Sn合金，并在348 K下浸炼4.50kmol m -3 h2so4，研究Sn含量对其腐蚀行为的影响。在自然浸没条件下，Pb-Ca-Sn合金的腐蚀电流受阴极反应控制，阴极反应涉及溶解氧的消耗。阳极反应主要由pbso4的生成和Sn的溶解组成。对于质量%Sn为0 ~ 0.2的Pb-Ca-Sn合金，99%的阳极电流用于前一反应。低锡合金栅格在高温硫酸溶液中形成易碎且强度低的硫酸盐是造成其严重腐蚀损伤的原因之一。另一方面，当Sn质量%≥0.3时，形成pbso4的电流随合金中Sn含量的增加而线性减小。对于Pb-0.08质量%Ca-1.2质量%Sn等高锡合金，随着Sn含量的增加，pbso4形成与阳极电流之比降低，机械强度可保持在较高水平，防止严重腐蚀。
{"title":"Influence of Sn Content on the Corrosion Behavior of Pb–Ca–Sn Alloys in High-Temperature Sulfuric Acid Solution","authors":"Masarni Taguchi, T. Hirasawa","doi":"10.2320/MATERTRANS1989.41.1307","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1307","url":null,"abstract":"Pb-0.08 mass%Ca-Sn alloys with a wide range of Sn contents were prepared, and then immersed in 4.50kmol m -3 H 2 SO 4 at 348 K to elucidate the influence of Sn content on their corrosion behavior. Under natural immersion, the corrosion current of the Pb-Ca-Sn alloys is governed by the cathodic reaction, which involves the consumption of dissolved oxygen. The anodic reaction consists mostly of PbSO 4 formation and Sn dissolution. For the Pb-Ca-Sn alloys with 0 ∼ 0.2 mass%Sn, 99% of the anodic current is used in the former reaction. The formation of the sulfate, which is noticeably fragile and low in strength, can be assumed to be one cause for the serious corrosion damage to the low-Sn alloy grids in high-temperature sulfuric acid solution. On the other hand, the current for the PbSO 4 formation decreases linearly with increasing Sn content in the alloys at about 0.3 mass% Sn or more. For the high-Sn alloys such as Pb-0.08 mass%Ca-1.2 mass%Sn, the ratio of PbSO 4 formation to the anodic current is lowered by the Sn content, and the mechanical strength may be maintained at a high level to prevent serious corrosion.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"1 1","pages":"1307-1311"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90988652","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 : 2000-10-20DOI: 10.2320/MATERTRANS1989.41.1360
Wen-Yue Liu, T. Okada, F. Inoko
Compressive deformation was applied to a coarse-grained Fe-30Cr alloy polycrystal at room temperature. Multiple slip occurred close to a grain boundary. Through the investigation of the activated slip systems, it was known that the dislocations which piled up against the grain boundary were mixed ones with a relatively large screw component. After annealing, many recrystallized grains (RGs) formed close to the original grain boundary. The orientations of more than 80% of the RGs were related to the deformed matrices by rotations about (110) axes normal to each common cross slip plane of the activated dislocations. Strain induced boundary migration did not occur. The preferred orientation of RGs was discussed in connection with the activity of slip systems.
{"title":"Influence of Activated Dislocations on Recrystallization near Grain Boundaries in Coarse-Grained Fe–30Cr Alloy","authors":"Wen-Yue Liu, T. Okada, F. Inoko","doi":"10.2320/MATERTRANS1989.41.1360","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1360","url":null,"abstract":"Compressive deformation was applied to a coarse-grained Fe-30Cr alloy polycrystal at room temperature. Multiple slip occurred close to a grain boundary. Through the investigation of the activated slip systems, it was known that the dislocations which piled up against the grain boundary were mixed ones with a relatively large screw component. After annealing, many recrystallized grains (RGs) formed close to the original grain boundary. The orientations of more than 80% of the RGs were related to the deformed matrices by rotations about (110) axes normal to each common cross slip plane of the activated dislocations. Strain induced boundary migration did not occur. The preferred orientation of RGs was discussed in connection with the activity of slip systems.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"94 1","pages":"1360-1365"},"PeriodicalIF":0.0,"publicationDate":"2000-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80664786","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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