田中 由紀子 バック。 株式会社 幻冬舎

We need to consider not only solid-liquid interface but also solid-solid crystalline interface for the structure of ceramics made by liquid phase sintering. Molecular dynamics simulations were performed to study six grain boundaries of α-alumina Al 2O 3 with a glassy phase of anorthite CaAl 2Si 2O 8 composition. As a result, it was found that the magnetization along the easy axis jumps up in magnitude by 3% at around 280 K. The diffusion constant of thin film was smaller than that of thick film. When the glassy film width was nm order, the atomic arrangement of the glassy phase was regular and the atomic diffusion behavior was approached that of a solid crystalline phase. It was found that the WC grain growth was more strongly inhibited with increasing Ti C,N content and with decreasing Ti C,N particle size. Diffusion constants depended on the thickness of the glassy film. When using Labusch model to predict solid solution strengthening improvement, an application of the isotropic strains by solute elements is generally assumed to estimate Fm value, which is the maximum interaction force between the solute atoms and dislocations. According to this analysis, it was clarified that Fm value of Ti-O and Ti-N materials was 6. It was also found that the magnetization along the easy axis increases as the lattice constant of the a-axis expands, which shows mostly good agreement with the experimental results under some assumptions. The case that one Ti C,N particle contacts plural WC grains was often observed, so that the pinning effect was considered to work by many Ti C,N particles neighboring one WC grain. The influence of strain in the Nd-Fe-B was investigated by using the structural phase transition of BaTiO 3 in films consisting of a Mo top layer 10 nm , Nd-Fe-B 30 nm , and a Mo bottom layer 20 nm deposited onto BaTiO 3 001 substrates by sputtering. The very important result that the pinning effect by Ti C,N addition enable to develop the new type of ultra-fine cemented carbide was obtained in this study. The saturated magnetization of the SiO 2-coated Fe nanoparticles with SiO 2 thickness of 2. We calculated excess energy, diffusion constant and ratio of excess volume with different thickness of the glassy film. Solid solution strengthening effect by oxygen O and nitrogen N atoms of α-titanium Ti materials was quantitatively evaluated using Labusch model by consideration of the experimental data. Well-defined SiO 2-coated Fe nanoparticles with various SiO 2 thickness from 1. First-principles calculations were applied to simulate the relationship between magnetization, magnetocrystalline anisotropy and the strain in the Nd-Fe-B main phase. The degree of inhibition by the addition of Ti C,N particle with about 0. In this study, Fm value was experimentally derived from the relationship between 0. This significant effect is certainly due to the lattice strain accompanying the structural phase transition of BaTiO 3 from orthorhombic to tetragonal. Excess volume was the maximum when the thickness of the glassy film was 0. The WC-Co cemented carbides with the addition of Ti C,N base particles with different sizes were fabricated by liquid phase sintering and their microstructures were mainly investigated in detail comparing the microstructure of the alloys with VC and Cr 3C 2 addition. Considering the results about the relationship between WC grain size and Ti C,N particle size and the analysis of Co phase composition, it was seen that the mechanism of grain growth inhibition by the addition of Ti C,N particles was the pinning Zener effect by the second phase particle, which was different from the mechanism for the addition of VC and Cr 3C 2 reported previously. When the thickness of the glassy film was thick adequately, excess energy corresponded to the energy of alumina-glass interface and they were different for each interface. It was found that excess energy for some grain boundaries exhibited a minimum. The saturated magnetization of the SiO 2-coated Fe nanoparticles increased with decreasing SiO 2 thickness. It is, however, difficult to exactly calculate Fm value for α-Ti materials with O and N solute atoms because the anisotropic strains are induced in α-Ti crystal with hcp structure by these elements.。

26

36