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Volume 51, Issue 10
Displaying 1-15 of 15 articles from this issue
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Harumitsu Makita, Shuji Hanada, Osamu Izumi1987 Volume 51 Issue 10 Pages 883-892
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe rolling and recrystallization textures and the mechanical properties of permalloy have been studied. The rolling texture showed copper type and primary recrystallization one did the cube orientation, in agreement with the previous work. Almost all the secondary recrystallization orientations were related to the primary recrystallization ones; Σ7, Σ13b and Σ21a in the CSL expression. Work hardnening rate and elongation of the cube-oriented permalloy were dependent on the orientation of the tensile axis.
Elongation of the ordered permalloy with cube orientation was smaller than that of the disordered one. Work-hardening rate and elongation of the cube-oriented permalloy were dependent on the orientation of the tensile axis. It was found by the tensile test using the ordered permalloy with cube-orientation that there was a tendency for the high angle boundary to fail preferentially in comparison with the low angle boundary and the tendency was enhanced by annealing under a low vacuum.View full abstractDownload PDF (2636K) -
Yoshinori Wakamatsu1987 Volume 51 Issue 10 Pages 893-900
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe equations determining inter- and intrinsic diffusion coefficients in vapor-solid couples accompanying volume changes on mixing are presented using ordinary space coordinate system of which the origin is taken at the vapor-solid interface after diffusion. The equations presented in this paper are less troublesome in calculation than that expressed using the non-laboratory coordinate system called the ξ system, that is, the total mole-fixed reference frame.
Among the equations which have been used for analysis of interdiffusion coefficients in sandwich-type diffusion couples, Balluffi’s equation can be applied to vapor-solid couples accompanying volume changes,if the origin of the space coordinate is taken at the vapor-solid interface before diffusion. Sauer and Freise’s equation cannot be applied to vapor-solid couples, because vapor-solid and sandwich-type couples differ in boundary condittons.View full abstractDownload PDF (1102K) -
Masamichi Miki, Yoshikiyo Ogino1987 Volume 51 Issue 10 Pages 901-906
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffects of B addition on the intragranular and cellular precipitations in a Cu-2 mass%Be alloy on aging at 523 and 623 K after quenching from 1093 K were investigated by means of hardness measurements, optical and electron microscopic observations, and X-ray analysis. The results obtained are as follows: The addition of 0.02-0.1 mass%B suppressed the formation of G.P. zones and retarded the precipitation of γ′ phase. The lattice parameter of the α solid solution of the B added alloy increased with the B addition. This result suggests that B exists interstitially in the α solid solution and suppresses the formation of G.P. zones and retards the precipitation of γ′ phase as a result of the strong interaction with vacancies. The formation and growth of grain boundary cells were suppressed by the addition of 0.02-0.05%B, but promoted by the excess addition of B, 0.1%.View full abstractDownload PDF (1790K) -
Yoshimasa Takayama, Tatsumi Tozawa, Hajime Kato, Norio Furushiro, Shig ...1987 Volume 51 Issue 10 Pages 907-910
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA new method is proposed to estimate the three-dimensional grain size distribution from the measured linear intercept length distribution. The method is developed on the assumption that the grain size distribution in three dimensions is a log-normal distribution. The three-dimensional grain size distribution is expressed as that of the “grain diameter” D defined as the equivalent volume diameter; the distribution of D is estimated from the arithmetic mean lnDg and the arithmetic standard deviation lnσg for the logarithm of D, lnD (where Dg is the geometric mean of D and σg is the gometric standard deviation for D). The estmation is based upon the theoretical distribution of linear intercept lengths which is derived from the numerical calculation in the tetrakaidecahedron grain structure model with a diameter distribution in a log-normal form. The values of Dg, and lnσg are determined by applying the discrete least squares method to the measured linear intercept length distribution on the basis of the calculated results. The present method enables us to evaluate the fundamental parameters of Dg, and lnσg defining three-dimensional distribution of grain size from measurements of linear intercept length distribubon.View full abstractDownload PDF (710K) -
Toshiki Kaneko, Yoshihito Maeda, Tetsuroh Minemura, Isao Ikuta, Hisash ...1987 Volume 51 Issue 10 Pages 911-915
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe color-change of splat cooled Ag-(40∼60)at%Zn alloy foils were studied by using chromametry, spectral reflectivity measurements and X-ray diffractometry. When the foil is quenched from 623 K and annealed in 473 K, it shows pink and silver colors, respectively. They locate between 5YR and 5R on CIE(1931) chromaticity diagram. The X-ray diffraction patterns imply that the pink and silver colors correspond to the β′ and ζ phases, respectively. At Ag-50 at%Zn, the color-change temperatures from pink to silver and from silver to pink are equal to 425 and 553 K, which correspond to the β′→ζ and ζ→β transition temperatures, respectively, and which show the composition dependence. The spectral reflectivity of pink color shows a characteristic absorption at the wavelength of 530 nm associated with the interband transition of electrons on the Fermi surface, whereas that of silver color shows no absorption. The color-change is determined by the difference of electronic structures of both phases.View full abstractDownload PDF (573K) -
Seiichi Muneki, Yoshikuni Kawabe, Junji Takahashi1987 Volume 51 Issue 10 Pages 916-922
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of the solution treatment in the range from two phase (α+β) to β-fields on the strength, ductility, and toughness of Ti-10V-2Fe-3Al alloy has been investigated. When the solution treatment was performed in the temperature range from 973 to 1173 K, the 0.2% yield strength showed a noticeable decrease at 1043 K or higher and was only about 450 MPa or less. In contrast with these variations the elongation showed a great increase.
It is considered that these variations of the 0.2% yield strength and elongation arise from the stress induced martensitic transformation due to the instability of the β phase matrix. After aging at 783 K for 28.8 ks, the 0.2% yield strength did not show any sharp decrease like that in the solution treated condition. Both elongation and reduction in area showed a considerable low values at 1073 K or higher. However, the detrimental effect of coarsening of β grain size was not detected from the mechanical properties because of their very small absolute values of ductility. On the other hand, the notch tensile strength and KIC were not affected by the microstructural change at the same strength level. Notch tensile strength was not affected by the strength but KIC showed a decrease with an increase of the strength level.
It was confirmed that the superior combination of strength, ductility, and toughness after aging treatment at 783 K for 28.8 ks was obtained with the solution treatment at sub-transus temperature of 1023∼1043 K.View full abstractDownload PDF (1519K) -
Seiichi Muneki, Yoshikuni Kawabe, Junji Takahashi1987 Volume 51 Issue 10 Pages 923-929
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of aging treatment on the microstructure and the mechanical properties of Ti-10V-2Fe-3Al alloy has been investigated. In order to investigate the effect of aged precipitates by excluding the effect of primary alpha precipitates, a solution treatment was performed at 1073 K which was just above the β-transus temperature. Although a remarkable increase in hardness was shown by aging from 573 to 673 K, the strength corresponding to the aged hardness was not obtained. It arises from the low stress fracture which was induced by the precipitation of the ω phase. When aged at 723 K, the tensile strength showed a maximum value of 1570 MPa but both elongation and reduction in area indicated 0%. Notch tensile specimens also indicated notch embrittlement behavior. When aged at 748 K or higher, the tensile strength decreased but both elongation and reduction in area increased with increase in aging temperature. The notch tensile strength showed the same decreases as that of the tensile strength.
It was confirmed that the aging treatment between 748 and 773 K for 28.8 ks gave the best combination of strength, ductility, and notch toughness after solution treatment in the beta phase field.View full abstractDownload PDF (2683K) -
Toshio Katagiri, Kyoko Fujii, Shinichi Ishiwata, Yasuyuki Ozeki, Eiich ...1987 Volume 51 Issue 10 Pages 930-934
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe gas sulphonitriding of iron and steel was studied by using ammonium sulphide as a sulphonitriding reagent. The results are as follows: (1) The sulphonitrided layer was obtained by heating the specimens at the temperature of 853 K for 3.6∼21.6 ks in the gas mixture of ammonia and resolved ammonium-sulphide carried by argon. (2) From the results of X-ray diffraction and the line analyses by an X-ray microanalyser, it was observed that the sulphonitrided layer consisted of FeS, ε-Fe2−3N, γ′-Fe4N and Fe3O4 which was considered to be formed by the oxidation reaction with H2O contained in ammonium sulphide solution. (3) The microhardnesses of sulphonitrided surface of all specimens of steel showed about 400 HV and at the center of the sulphonitrided layer, the highest microhardness value of SACM 1 was determined to be 1145 HV and that of SCM 440 was 930 HV.View full abstractDownload PDF (1080K) -
Genjirou Motoyasu, Tetsuichi Motegi, Atsumi Ohno1987 Volume 51 Issue 10 Pages 935-940
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to obtain the basic data on the ingots of the Sn-Zn solders, the Sn-6.5, 9 and 30 mass%Zn alloys ingots were obtained by horizontally continuous casting of the O.C.C. (Ohno Continuous casting) and conventional casting. Each ingot was examined by macro- and microstructures, plastic working properties and mechanical properties (tensile strength, elongation, reduction in area, and hardness).
All the O.C.C. ingots had a mirror surface and a unidirectionally solidified structure without equiaxed crystals. The wires, deformed by drawing up to 97% reduction in cross sectional area, could be obtained from the O.C.C. ingots at the room temperature without breaks and they had a good surface condition. In addition, the mechanical properties of the O.C.C. ingots and their wires were superior to the conventional ingots and their wires.View full abstractDownload PDF (1814K) -
Masayuki Kudoh, Tatsuya Ohmi, Tadayoshi Takahashi1987 Volume 51 Issue 10 Pages 941-947
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe transition from columnar to equiaxed crystals was examined for two different types of ingots on the basis of the macrostructures and cooling curves. In the first case the molten metal was conventionally cast for different pouring temperature. In the second case the molten metal, which was kept at constant temperature, was forced to cool with water spray. It resulted in the increased supercooling and the change in cooling rate crossing though the equilibrium liquidus temperature, in the process of the transition. It is considered that the transition occurs when the growth of columnar dendrites is delayed in spite of the increase in supercooling, and crystallization occurs in the supercooled region in front of the columnar dendrites due to a temporary increase in cooling rate. This shows that solidification proceeds discontinuously. Similar phenomenon was also observed in the case of the formation of a columnar zone in the conventionally cast ingot. The transition from fine to coarse crystals in the columnar zone occurred when the supercooled region was extended in the neighborhood of the inner walls of the mold.View full abstractDownload PDF (1649K) -
Masayuki Kudoh, Tatsuya Ohmi, Tadayoshi Takahashi1987 Volume 51 Issue 10 Pages 948-955
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this study, a primary solidifying alloy was added with a secondary melt of a lesser volume. The former and the latter were termed as the primary and secondary molten metals, respectively, and the process as duplex casting. Al-3 mass%Si alloy was used as the primary molten metal, and pure Al and Al-3 mass%Si alloy were used as the secondary molten metal. The time interval between pourings of the primary and secondary molten metals in the mold varied from 4 to 15 s. The results showed finer equiaxed crystals with the increase in pouring interval. The equiaxed crystals were finer, when Al was used as the secondary molten metal, because of the extension of the constitutionally supercooled region. It was also observed that there was an optimum time interval for the extension of the equiaxed region when Al-3 mass%Si alloy was used as the secondary molten metal; it was shorter when Al was used.View full abstractDownload PDF (2570K) -
Takashi Itoh, Yoshimoto Wanibe, Hiroshi Sakao1987 Volume 51 Issue 10 Pages 956-964
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present study deals with the characterization in the particle size distributions of metallic powders. The Rosin-Rammler distribution is used as a particle size distribution function for its good applicability. First, a new number based expression is introduced for a modified Rosin-Rammler distribution which has been led in the previous paper, and compared with the previous expression. Next, the calculating equations are presented for the various mean particle diameters of the powders, having the distributions. Furthermore, the calculation can be extended to the cases of classification and blending of those powders.
The results are summarized as follows:
(1) New number based approximate equation (16) is at least ten times more accurate for the expression of the modified Rosin-Rammler distribution than the equation (11) in the previous paper.
(2) The equations for the calculation of the various mean particle diameters of the distributions are tabled in Table 3.
(3) The various mean particle diameters can be also calculated in the cases of classification and blending of the powders, having the distributions.
The present results are also applicable to other distributions such as grain, pore sizes, etc.View full abstractDownload PDF (1110K) -
Hiroyuki Eda, Taketo Sakuma, Hajime Suto1987 Volume 51 Issue 10 Pages 965-970
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to make clear that the stress-induced-transformation from tetragonal to monoclinic is the origin of high fracture toughness of Y2O3 partially stabilized zirconia (Y-PSZ), KIC-values of arc-melted Y-PSZ’s were obtained by means of an indentation method, and the relationship between KIC and the stability of or the amount of tetragonal phase was obtained. An “as-cast” 1.8 mol%Y2O3 specimen was most tough, but after annealing, the KIC decreased as the tetragonal phase became extremely unstable. Additionally, the composition ranges of high toughness in the ZrO2-YO1.5-X(X: CeO2, CaO and MgO) ternary systems are shown.View full abstractDownload PDF (2381K) -
Nobuya Iwamoto, Norimasa Umesaki, Shigeki Endo1987 Volume 51 Issue 10 Pages 971-978
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMicrostructures of two Al2O3-12 mol%ZrO2 composite powders prepared by blending† and fusing†, respectively, were investigated by means of X-ray diffraction and laser-Raman spectroscopy before and after plasma spraying. Furthermore, the stress-induced transformation from the tetragonal (t-ZrO2) to the monoclinic (m-ZrO2) phase in the coatings, caused by the Vickers indentation, cracks and fracture, was directly observed by the use of laser-Raman microprobe.
The results obtained were as follows:
(1) The structural behavior of the B-coating was almost the same as that of a single alumina or zirconia coating prepared by plasma spraying.
(2) The T-ZrO2 phase was predominant in the B-coating and was a metastable phase as the result of plasma spraying. The laser-Raman microprobe measurement indicated that the transformation behavior in the B-coating caused by a Vickers indentation was observed in the central area and around cracks of an indent due to stress concentration.
(3) In the F-coating the α-Al2O3 phase was mostly retained after plasma spraying, while a large amount of the m-ZrO2 phase was formed. These results indicate that the microstructures of the alumina-zirconia coatings are dependant on the state of the starting ceramic powders.
†We named the alumina-zirconia coatings produced from blended and fused powders “B-coating” and “F-coating”, respectively.View full abstractDownload PDF (1096K) -
Moritaka Hida, Eiichi Sukedai1987 Volume 51 Issue 10 Pages 979-980
Published: 1987
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (239K)
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