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金沢大学理工研究域機械工学系, The influence of prior cold work (90% reduction) on the length change and precipitation behaviour of a Cu-1.8wt%Be-0.2wt%Co alloy aged at 320C up to 350 h has been investigated. The alloy gradually expands to a maximum and then contracts during ageing. The maximum expansion is attributable to both the expansion due to the loss of Be solute atoms and the contraction due to precipitation of the [image omitted], I, m and ' phases. The subsequent contraction results from the decrease in amounts of the [image omitted] and m phases and the increase in amount of the ' phase. The new-found m phase, consisting of alternate Be and Cu matrix layers parallel to the matrix {001}, is body-centred monoclinic with a = b = 0.263 nm and c = 0.279 nm and = 83, and aligns with the matrix according to the Bain orientation relationship. The Guinier-Preston (GP) zone transforms continuously to the m or I phase via '' and [image omitted]. The transformation from the GP zone to ' via '', [image omitted] and I is retarded in comparison with that for the un-deformed alloy.全文公開201002

Length-change measurements using Cu–0.9 wt% Be alloy single crystals containing only the disc-shaped Guinier–Preston (GP) zones parallel to the Cu matrix (001)α plane have enabled estimation of the misfit strains of γ″, , γ′ and γ precipitated phases in directions parallel and perpendicular to the GP zone, e 11 = e 22 and e 33. The absolute values of e 33 = −0.09 and −0.08 for the respective γ′ and γ phases, experimentally estimated, are far smaller than e 33 = −0.25 calculated using lattice parameters of the γ′ and γ phase and the Cu matrix. The presence of the array of misfit dislocations at the interfaces between the phases and matrix results in the smaller absolute values of e 33. Length-change measurements have also been carried out for Cu–1.8 wt% Be–0.2 wt% Co alloy polycrystals aged at 320 and 500°C. The alloy aged at 320°C initially exhibits a decrease in length change (elongation), then plateau behaviour, a subsequent slight increase and, finally, a plateau. The first contraction and the sl...

Summary China's economic growth has been remarkable since the economic reform started in 1978. It has incorporated transitional processes to its long‐lasting institutional system, which include the shift to a market economy, rapid industrialization, and urbanization, as well as the dramatic reforms of its educational system. While there is ongoing debate whether such economic performance is driven chiefly by productivity growth or by factor accumulation, there have been studies, nonetheless few, that have taken institutional factors and informatization into account. While the current low levels of human resources and urbanization have impeded China's development, the conspicuous development of education and urbanization over the last two decades could become the primary institutional factors for the acceleration of future economic growth. The Chinese government's comprehensive informatization strategy is considered to be the accelerating factor of education and urbanization, leading to a virtuous cycle be...

A stress-oriented formation of plate-shaped Guinier–Preston (GP) zones in single crystals of a Cu–0.9 wt.% Be alloy aged at 200°C has been found. A compressive stress applied in the [001] direction assists the formation of the GP zones perpendicular to the [001] axis, while a tensile stress results in the preferential formation of the GP zones parallel to the stress axis. The applied stress strongly affects the nucleation of the GP zones. Free ageing at 275°C after compressive-stress ageing at 200°C produces plate-shaped γ′′ precipitates perpendicular to the stress axis, indicating a continuous change in the structure of the GP zones into that of the γ′′ phase. From length-change measurements during ageing, the misfit strains of the GP zone or γ′′ precipitate in directions parallel and perpendicular to the plate plane are estimated, respectively, as −0.01 and −0.10 for the GP zone and −0.01 and −0.11 for the γ′′ precipitate.

The application of external stress during ageing induces the oriented formation of disc-shaped aggregates consisting of rod-shaped Ag precipitates and a Cu matrix on {100} planes in single crystals of a Cu–5.7 wt% Ag alloy. Tensile stress along the [001] axis induces preferential formation of the aggregates perpendicular to the [001] axis and compressive stress induces the same parallel to the stress axis. The stress-orienting effect is determined during the initial stage of precipitation, when the formation of the aggregates starts on dislocations. The experimental result can be understood if the misfit strain of the aggregates in a direction perpendicular to the disc plane is larger than that in the parallel direction. This idea is supported by length-change measurements during ageing.

The formation and growth of disc-shaped aggregates consisting of rod-shaped Ag precipitates and Ag-depleted Cu matrix in the {100} planes in single crystals of a Cu–5.7 wt% Ag alloy have been investigated by transmission electron microscopy. The formation of the aggregates begins on dislocations and their growth progresses through a discontinuous process without existing dislocations. The aggregates grow at a constant velocity in an isothermal condition, maintaining a constant inter-rod spacing. A kinetic analysis of the aggregate growth using the model of Zener has yielded values of the diffusivity of Ag in Cu. The estimated activation energy for diffusion is 185 kJ mol−1.

Summary Japan's economic clusters are characterized by their high level of diversity. In essence, Japanese economic clusters are not limited to single industries; they comprise numerous manufacturing industries and firms which cluster in specific heterogeneous economic zones, vice political boundaries. Japanese manufacturing sectors are showing an increased level of diversity, resulting in the spread of experience and knowledge among clusters, and sustained growth at the point of industrial structural transformation. Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT) proposed the creation of intellectual clusters for the purpose of promoting research and development (R&D) activities resulting in the stimulation and development of new technologies. The Ministry of Economy Trade and Industry (METI) is also proposing the industrial cluster plan with the aim to promote the local rebirth and revitalization of the Japanese industrial sector. This paper proposes a methodological analys...