Materials Transactions Jim最新文献_第10页

First-Principles Calculation on Dissociation of Hydrogen Molecule in Nickel 氢分子在镍中解离的第一性原理计算

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1114

Jing-Zhi Yu, Qiang Sun, Qian Wang, Utako Onose, Y. Akiyama, Y. Kawazoe

引用次数: 5

Hydrogen-induced disproportionation of Zr2Co 氢诱导Zr2Co歧化反应

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1146

M. Hara, R. Hayakawa, Kuniaki Watanabe

引用次数: 7

Microstructure and tensile properties of rolled Mg-5.5 mass%Zn-0.6 mass%Zr alloy 轧制Mg-5.5质量%Zn-0.6质量%Zr合金的组织与拉伸性能

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1154

T. Mohri, T. Nishiwaki, T. Kinoshita, H. Iwasaki, M. Mabuchi, M. Nakamura, T. Asahina, T. Aizawa, K. Higashi

引用次数: 9

Thickness measurement of amorphous SiO2 by EELS and electron holography 用EELS和电子全息法测量非晶SiO2的厚度

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1129

Chang-Woo Lee, Y. Ikematsu, D. Shindo

引用次数: 4

Magnetic Domain Structures of Nd-Fe-B based Permanent Magnets Studied by Electron Holography and Lorentz Microscopy 用电子全息和洛伦兹显微镜研究Nd-Fe-B基永磁体的磁畴结构

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1132

Young-Gil Park, D. Shindo, M. Okada

引用次数: 4

An MD Simulation of the Atomistic Processes of Movement and Agglomeration of Vacancy Clusters in Nickel at 1300 K 1300k下镍中空位团簇运动和团聚原子过程的MD模拟

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1168

R. Nishiguchi, Y. Shimomura

{"title":"An MD Simulation of the Atomistic Processes of Movement and Agglomeration of Vacancy Clusters in Nickel at 1300 K","authors":"R. Nishiguchi, Y. Shimomura","doi":"10.2320/MATERTRANS1989.41.1168","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1168","url":null,"abstract":"Computer simulations of molecular dynamics (MD) were used to study the clustering of vacancies in nickel. This was carried out in order to investigate the atomistic processes of vacancy agglomeration in irradiated metals. Simulations were carried out using DYNAMO ver. 8.5 code, by implementing the potential of the embedded atom method (EAM). Firstly, a perfect crystal was thermalized at 1300, 1500, 1700 and 1800 K. Next, four triangular vacancy clusters whose sizes were 10 were introduced on the (111) planes at randomly selected positions. MD simulations were performed using a very small time step of outputs to observe the atomistic processes of the movement of each vacancy. It was found that the vacancy clusters moved and agglomerated whilst maintaining the individual clusters. Thus, a vacancy did not evaporate from a cluster to be absorbed into a larger cluster. There were three different processes in the agglomeration of the vacancy clusters. One was an atom caged in a tetrahedral structure of vacancies moved to another lattice site. Another was an atom caged in a octahedral structure of vacancies moved to another lattice site. The other was an atom moved along a (110) row.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"46 1","pages":"1168-1171"},"PeriodicalIF":0.0,"publicationDate":"2000-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79310853","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}

引用次数: 1

Phase equilibria and amorphous phase formation in the Ni-Nb-P ternary alloy system Ni-Nb-P三元合金体系的相平衡与非晶相形成

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1232

M. Lee, S. Yi, D. Kim

引用次数: 0

Electromagnetic Microwave Absorption of α-Fe Microstructure Produced by Disproportionation Reaction of Sm 2 Fe 7 Compound sm2fe7化合物歧化反应产生α-Fe微观结构的电磁微波吸收

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1172

T. Maeda, S. Sugimoto, T. Kagotani, D. Book, M. Homma, H. Ota, Y. Houjou

{"title":"Electromagnetic Microwave Absorption of α-Fe Microstructure Produced by Disproportionation Reaction of Sm 2 Fe 7 Compound","authors":"T. Maeda, S. Sugimoto, T. Kagotani, D. Book, M. Homma, H. Ota, Y. Houjou","doi":"10.2320/MATERTRANS1989.41.1172","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1172","url":null,"abstract":"The electromagnetic wave absorption properties of a magnetic powder with a fine α-Fe structure, produced by the disproportionation of Sm 2 Fe 17 , were investigated in the GHz frequency range. A fine, sub-micrometre α-Fe/SmH 2 structure was formed from the Sm 2 Fe 17 compound after disproportionation in a hydrogen atmosphere. The grain size of the α-Fe phase was calculated by X-ray diffraction line broadening analysis, to he about 30nm. In this way, a magnetic powder with a line structure of α-Fe was obtained. This powder was then heated in air in order to oxidize the SmH 2 , with the result that an α-Fe/SmO two-phase microstructure was obtained. Toroidally shaped epoxyresin composites were made from this powder, and the microwave absorption properties of these samples were measured. As a result, the disproportionated samples (heated in hydrogen at 873 K for 1 hour, milled for 30 minutes and oxidized at 473 K for 2 hours in the air) exhibited electromagnetic wave absorption (R.L. < -20 dB) in the frequency range 0.75 to 1.3 GHz, for absorber thicknesses ranging from 12.5 to 7.5 mm, respectively. An undisproportionated sample did not show any electromagnetic wave absorption in this frequency range.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"33 1","pages":"1172-1175"},"PeriodicalIF":0.0,"publicationDate":"2000-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78461089","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}

引用次数: 18

Protium absorption properties of Mg-Al based ternary alloys 镁铝基三元合金的吸氢性能

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1142

H. Takamura, T. Amemiya, A. Kamegawa, M. Okada

{"title":"Protium absorption properties of Mg-Al based ternary alloys","authors":"H. Takamura, T. Amemiya, A. Kamegawa, M. Okada","doi":"10.2320/MATERTRANS1989.41.1142","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1142","url":null,"abstract":"The protium absorption properties of Mg-Al-Cu, Mg-Al-Ni, and Mg-Al-Si alloys have been investigated in conjunction with mi crostructures and the phases present. The alloys were prepared by a flux-melting technique. Mg-Al-Cu as-cast alloys were found to consist of Mg, MgAlCu, and Mg 17 Al 12 phases In addition to the Mg phase, the Mg 17 Al 12 phase also contributed to the protium absorption by undergoing a disproportionation reaction. The protium absorption capacity of these Mg-Al-Cu alloys ranged from 2.2 to 4.6 mass% at 623 K, and was found to be controlled by the amount of Mg and Mg 17 Al 12 phases present. For the Mg-25Al-5Ni and Mg-25Al-5Si as-cast alloys, Mg and Mg 17 Al 12 phases were found to be present. In addition, a Mg 2 Si phase was observed in the Mg-25Al-5Si alloy. The protium absorption capacities of the Mg-25Al-5Ni and Mg-25Al-5Si alloys were 3.6 and 3.9 mass%, respectively, Unlike the Mg-Al-Cu alloys, the Mg 17 Al 12 phase in Mg-Al-Ni and Mg-Al-Si alloys partially remained even after protium absorption. This difference in disproportionation behavior seems to be due to the small amount of solute elements in the Mg 17 Al 12 phase, and/or to the microstructure.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"47 1","pages":"1142-1145"},"PeriodicalIF":0.0,"publicationDate":"2000-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82710092","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}

引用次数: 3

Effect of W addition on compressive strength of Nb-10Mo-10Ti-18Si-base in-situ composites 添加W对nb - 10mo - 10ti - 18si基原位复合材料抗压强度的影响

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1125

J. Sha, H. Hirai, T. Tabaru, A. Kitahara, Hidetoshi Ueno, S. Hanada

{"title":"Effect of W addition on compressive strength of Nb-10Mo-10Ti-18Si-base in-situ composites","authors":"J. Sha, H. Hirai, T. Tabaru, A. Kitahara, Hidetoshi Ueno, S. Hanada","doi":"10.2320/MATERTRANS1989.41.1125","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1125","url":null,"abstract":"Niobium solid solution/niobium silicides in-situ composites are expected to have applications in the future as high-temperature structural materials. To improve the high temperature strength further, we tried to add tungsten to Nb-10Mo-10Ti-18Si eutectic alloy by replacing Nb with 0, 5, 10 and 15 mol%W, The samples were prepared by arc casting and some of them were directionally solidified by the floating zone melting technique at a growth rate of 15 mm/h, After annealing at 1870 K for 100h, the microstructure, Vickers hardness and high-temperature compressive strength were examined. The samples without W consisted of eutectic Nb solid solution and (Nb, Mo, Ti) 5 Si 3 silicide, while primary Nb solid solution appeared as a result of substituting W for Nb. The microstructure of directionally solidified samples was coarse and oriented in the direction of growth, but they did not show the typical microstructure often observed in the case of directionally solidified materials. The Vickers hardness increased with increasing W content. The 0.2% yield strength (σ 0.2 ) and the specific 0.2% yield strength (σ 0.25 ) (σ 0.2 divided by the density) at 1670 K increased markedly with increasing W content. The directionally solidified samples showed higher σ 0.2 and σ 0.2S than the arc-cast samples. Even at 1770 K, the directionally solidified sample with 15 mol% W showed σ 0.2 of about 650 MPa.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"17 1","pages":"1125-1128"},"PeriodicalIF":0.0,"publicationDate":"2000-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85450593","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}

引用次数: 13