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

Microstructure and Mechanical Properties of MoSi2/Nb Composites Made by MA-Pulse Discharge Sintering ma脉冲放电烧结MoSi2/Nb复合材料的组织与力学性能

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1268

Y. Park, H. Hashimoto, Y. Hahn

{"title":"Microstructure and Mechanical Properties of MoSi2/Nb Composites Made by MA-Pulse Discharge Sintering","authors":"Y. Park, H. Hashimoto, Y. Hahn","doi":"10.2320/MATERTRANS1989.41.1268","DOIUrl":"https://doi.org/10.2320/MATERTRANS1989.41.1268","url":null,"abstract":"MoSi 2 is one of the most promising candidates for high-temperature structural materials because of its high melting point and excellent oxidation resistance. However, the low room temperature fracture toughness and ductility, etc., still remain as major disadvantages to potential high temperature structural applications. MoSi 2 composites containing Nb have shown a great improvement in mechanical properties, especially in fracture toughness, over the monolithic MoSi 2 . However, the addition of refractory metals such as Nb or W has not been that acceptable because of the high reactivity of these additions with the MoSi 2 matrix, and the deleterious effect of reducing oxidation resistance and increasing density. Also, Nb reinforced MoSi 2 composites resulted in a penalty with decreasing strength, both at room and elevated temperatures. In the present study, MoSi 2 and MoSi 2 -Nb powders with a fine grain size were prepared by mechanical alloying. In order to retain the fine microstructure in the consolidated samples, pulse discharge sintering was used to consolidate these powders at a lower sintering temperature compared to that of the conventional hot pressing or HIP. The grain size of the consolidated MoSi 2 -10Nb composite was 0.18 to 1.2 μm, which was finer than that of monolithic MoSi 2 , 1.5 to 3.0 μm. The formation of the (MoNb) 5 Si 3 phase was pronounced in the Nb added composites, and this phase seemed to be formed during the sintering process. Both monolithic MoSi 2 and MoSi 2 -10Nb composites from the mechanically alloyed powders showed a significant amount of plastic deformation in a bending test at 1073 K. The yield stress of the Nb added alloy was higher than that of the monolithic MoSi 2 , which may be caused by the refinement of the microstructure.","PeriodicalId":18264,"journal":{"name":"Materials Transactions Jim","volume":"5 1","pages":"1268-1273"},"PeriodicalIF":0.0,"publicationDate":"2000-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85752940","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: 6

Unique Shapes of Micro-Pits Formed in an Al-Pd-Mn Icosahedral Quasicrystal by Anodic Etching 阳极蚀刻Al-Pd-Mn二十面体准晶体中独特形状的微凹坑

Materials Transactions Jim Pub Date : 2000-09-20 DOI: 10.2320/MATERTRANS1989.41.1221

Kaichi Saito, S. Sugawara, Tomonori Sato, J. Guo, A. Tsai

引用次数: 3