V マゲ ノ スプリング バック ニ カンスル ケンキュウ

The relationships between stress and strain, and r-values in three directions of thin steel plates are obtained by simple tension test. Using these results, the first stage bending by V-form die are analyzed by the relationship between curveture and bending moment, which considered anisotropy of material. A new method for analyzing the bending are shown. Stroke (Y), Load (P), Spring-back (△θ) and Bending-angle (θ) are calculated by the method and compared with their experimental values. The calculated results about Y-△θ and Y-θ are good agreement with experimental values, respectively

ジュンアンテイ TI MO ゴウキン ノ エンセイ ト オウリョク ユウキ セイセイブツ ニ カンスル ケンキュウ

The relationships between the mechanical properties and the thermal instability, and the influence of the rolling on Ti-5,14 and 20wt% Mo alloys quenched are studied by hardness testing. The deformation behaviours on these alloys are done in tensile testing at the temperature-range from 77K to 300K. The results obtained are as follows ; (1) It is appeared from the dependence of hardness changes upon the isochronal ageing temperature that in Ti-14wt% Mo alloy the thermal instability is the largest and the ω phase is formed. (2) By the rolling, the formation of ω phase in Ti-14wt% Mo alloy is appearently promoted, and this phenomenon is recognized up to 10% reduction but not for 30% reduction. (3) In tensile testing, it is appeared that Ti-14wt% Mo alloy is homogeneously deformed in twinning, and Ti-20wt% Mo alloy is locally done in slipping. (4) Ti-14wt% Mo alloy has the excellent mechanical properties having remarkable elongation and linear work hardening rate, however Ti-20wt% Mo alloy has small elongation

TEM observation of precipitates and their role to mechanical properties in Ti-5553 alloy heated to some temperatures up to 923 K

A Ti-5553 specimen was continuously heated to 923 K and simultaneously in-situ HEXRD profiles were taken. In addition, specimens heated at the same rate to several temperatures up to 923 K and further quenched were observed by transmission electron microscopy. Based on both results obtained, transformation sequence was clarified, precipitations of ω-, α”iso- and α-phases were confirmed, and size and density of these precipitates were measured. Hardness values of those specimens were also measured. The hardening mechanism was considered as shearing-mechanism for specimens aged at lower temperatures and by-pass one for specimens aged at higher temperature. An attempt of distinction between α”iso - and α-precipitates was also tried. Both precipitates were in needle-like shape and a possibility was suggested by measuring angles between two needle-shape precipitates on {110} of the matrix and comparing with each other

TEM observation of precipitates and their role to mechanical properties in Ti-5553 alloy heated to some temperatures up to 923 K

A Ti-5553 specimen was continuously heated to 923 K and simultaneously in-situ HEXRD profiles were taken. In addition, specimens heated at the same rate to several temperatures up to 923 K and further quenched were observed by transmission electron microscopy. Based on both results obtained, transformation sequence was clarified, precipitations of ω-, α”iso- and α-phases were confirmed, and size and density of these precipitates were measured. Hardness values of those specimens were also measured. The hardening mechanism was considered as shearing-mechanism for specimens aged at lower temperatures and by-pass one for specimens aged at higher temperature. An attempt of distinction between α”iso - and α-precipitates was also tried. Both precipitates were in needle-like shape and a possibility was suggested by measuring angles between two needle-shape precipitates on {110} of the matrix and comparing with each other