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Volume 41, Issue 3
Displaying 1-12 of 12 articles from this issue
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Taichi KAMIJO, Akihiko FUJIWARA, Hideaki TANAKA, Atsushi TAGAYA1991 Volume 41 Issue 3 Pages 147-151
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSAluminum single crystals in the (112) [111] orientation were cold-rolled to 99% reduction. The main component of rolling textures changed from the initial orientation towards (4 4 11) [11 11 8] orientation above 80% rolling but it was sharp up to the maximum reduction. The weak intensity areas were observed spreading over the pole figures. The minor component which was symmetrical to the main component with respect to the transverse direction, was formed at 90% rolling and developed with increasing reduction. The deformation structure of a totated cube orientation was observed in the (100) pole figure of the crystal cold-rolled 99%. The recrystallization textures were composed of a (1 1 10) [7 3 1] orientation which was appropximately related to the cube orientation by 22° rotation around the normal direction. Any orientation change from (1 1 10) [7 3 1] to (001) [100] was not found with an increase in rolling reduction. The formation of the rotated cube texture is attributed to preferential nucleation from the deformation structure in the same orientation. The deformed matrix of S-orientation might be required for development of the cube texture of good symmetry.View full abstractDownload PDF (569K) -
Tetsuya TAKAAI, Kazuki KATOH, Yoshihiro NAKAYAMA1991 Volume 41 Issue 3 Pages 152-157
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSSuperplastic deformation behaviours in superplastic Zn-22%Al eutectoid alloy were investigated. Smooth and notched specimens having the thickness of 1, 2 and 3mm were applied in the present experiment in view points of the change of true strain rate and m values during the course of the tensile superplastic deformation and variation of the fracture elongations. The results are summarized as follows: (1) Superplastic deformation of the smooth specimens was reasonably explained by dividing the deformation into sequential five steps. (2) Superplastic deformation of the notched specimens was reasonably explained by dividing the deformation into sequential two steps without passing the first three steps observed in case the smooth specimens. (3) Fracture elongations of the smooth specimens were effected by the variation of the specimen thickness and increased by 12 to 25% with the increase of the specimen thickness from 1 to 3mm. (4) The fracture elongation of the notched specimens was also effected by the specimen thickness and increased by 2 to 20% with the increase of the thickness of the notched specimen.View full abstractDownload PDF (658K) -
Yoshiki TSUNEKAWA, Yoshinobu KOHNO, Masahiro OKUMIYA, Itaru NIIMI1991 Volume 41 Issue 3 Pages 158-163
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe pre-mixture of elemental powers of Ti and Al was supplied for direct fabrication of titanium aluminide layers on SS41 substrates by the method of low pressure plasma spraying (LPPS) with Ar+H2 mixed plasma gas. The Al content of mixed powders was changed from 10 to 63mass%. There are three kinds of titanium aluminides formed in the intermetallic compound layers fabricated by LPPS. The sprayed titanium aluminide layers with mixed powders of 18-27mass%Al are mainly composed of Ti3Al. The sprayed layers with 36-45mass%Al are composed of TiAl and small amounts of Ti3Al and TiAl3, and one with 63mass%Al is mainly TiAl3. Micro-hardness of the as-sprayed titanium aluminide layers at 373K decreases gradually with increase of Al content. Hardness of the sprayed layers containing less than 18mass%Al drops down rapidly at 673K due to retained Ti in the layers. However, hardness of the layers which were sprayed with mixed powders of 10-18mass%Al increases after vacuum annealing at 1173K for 86.4ks, because of an alteration of retained Ti into harder Ti3Al. Consequently, LPPS offers one of the promising fabrication methods of intermetallic compounds.View full abstractDownload PDF (667K) -
Yoshiki TSUNEKAWA, Yoshinobu KOHNO, Masahiro OKUMIYA, Itaru NIIMI1991 Volume 41 Issue 3 Pages 164-169
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe pre-mixture of elemental powders of Ti and Al was supplied for direct fabrication of titanium aluminide matrix composite layers on SS41 substrates by the application of reactive low pressure plasma spraying (RLPPS) with N2+H2 mixed plasma gas. The Al content of mixed powders was changed in the range of 10-63mass%. Three kinds of titanium aluminides as matrices appear in the sprayed intermetallic matrix composite (IMC) layers formed with mixed powders, namely Ti3Al, TiAl and TiAl3, and also several kinds of nitrides as reinforcements. For example, matrices in the sprayed IMC layer with the mixed powder of 36mass%Al are mainly composed of TiAl, and small amounts of Ti3 Al, TiAl3 and Al phases also appear, by contrast a principal nitride in the layer is Ti2AlN. Both TiAl and Ti2AlN increase in amount after vacuum annealing at 1173K for 86.4ks. Micro-hardness of the as-sprayed IMC layers is higher than that of titanium aluminide layers containing no nitrides. The IMC layers with varying Al contest show the minimum room temperature hardness at about 45mass%Al. Hardness at 673K is not depend on Al content in the IMC layers, but approximately constant. Hence, it is thought that RLPPS offers one of the promised fabrication methods of IMC layers.View full abstractDownload PDF (955K) -
Naotsugu INAKAZU, Hirofumi INOUE, Yasuyuki KANENO1991 Volume 41 Issue 3 Pages 170-177
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe recrystallization textures of cold drawn aluminum alloys (Al-0.11%Si, Al-0.26%Fe, Al-0.27%Fe-0.11%Si) were determined by means of the orientation distribution function (ODF). The changes in texture with annealing temperature were interpreted by examining the interrelation between recrystallization and precipitation. The drawing textures of all the samples are mainly composed of the <111> fiber component. In the case of Al-Si, silicon exists in the solid solution at high and medium temperatures (623-723K), therefore, the <111> component is sharpened and the recrystallization textures are composed of the strong <111> component and the weak <100> one. On the other hand, precipitation of silicon participates in recovery and recrystallization at low temperatures (523-573K) so that the <100> component nearly equals to the <111> one in intensity. Al-Fe shows the strong <111>+weak <100> fiber texture in the all ranges of annealing temperatures, though the <111> component is stronger at a high temperature (723K), where precipitation occurs after recrystallization, than at low and medium temperature (573-673K), where it does before recrystallization. For Al-Fe-Si, the recrystallization textures are almost the same as those of Al-Fe except for weakening in orientation density.View full abstractDownload PDF (1121K) -
Hisakimi NOTOYA, Shigeru YAMADA, Yuzo TAKATSUJI, Ichizo TSUKUDA, Hidey ...1991 Volume 41 Issue 3 Pages 178-183
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSVarious aluminum alloys (2011-T8, 3003-H14, 4032-T6, 5056-H14, G67-T6, 7075-T6 and Al-17%Si-T6) were turned with K10 and diamond compact tools to examine the cutting behavior under wide range of cutting conditions. The effects of mechanical properties (hardness, tensile strength shear stress of high temperature and coefficient of friction for K10 tool against work materials) of these alloys on cutting forces, chip forms and finished surface roughness were discussed. Chip forms and cutting forces depended on the coefficient of friction on the rake face of K10 tool at high temperature. Cutting forces and chip forms cut with diamond compact tool differed from those with K10 tool.View full abstractDownload PDF (686K) -
Goroh ITOH, Shigeru KURAMOTO, Motohiro KANNO1991 Volume 41 Issue 3 Pages 184-191
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSTensile properties at 77 and 4.2K have been studied in Al-4.4%Zn-1.4%Mg alloys containing copper up to 1.5% both in under-aged and over-aged conditions. The ductility at a fixed strength level was significantly improved by the copper addition at both temperatures under both aging conditions. Fractographic observations revealed that the fraction of intergranular fracture decreased with increasing copper content, and that intergranular fracture surface consisted of ledges instead of micro-dimples. According to TEM and SEM observations after deformation, intense slip bands were seen in the copper-free alloy while the distribution of slip bands was relatively uniform in the copper-containing alloys. Microstructures adjacent to grain boundaries were also examined, but were considered to exert a minor effect. Thus the ductility improvement by the copper addition, connected with the suppression of intergranular fracture, was ascribed to the reduction in the stress concentration at the grain boundaries through the uniform distribution of slip bands.View full abstractDownload PDF (5207K) -
Takeshi MURAKAMI, Akihiko KAMIO, Tsuneo TAKAHASHI1991 Volume 41 Issue 3 Pages 192-196
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSMicrosegregation, homogenization behavior and aging characteristics were investigated in AZ91D magnesium alloy solidified in water-cooled copper mold. Specimens were extracted from a location 1mm away from chill plate because the microstructures with dendrite cell size from 10μm to 15μm were typical microstructure of diecastings. Minimum concentration of aluminum and zinc at a center of dendrite cell and amount of non-equilibrium eutectics crystallized at inter-dendrite cells were detected by means of X-ray microprobe analysis. Minimum concentration of aluminum and zinc were 4.5wt% and 0.35wt% respectively, and approximate homogenization was attained at 683K for 1h. Hardening was observed in aging of the alloy at the temperature from 373 to 443K without homogenization, the time to attain the maximum hardness being longer than the homogenized alloy.View full abstractDownload PDF (1782K) -
Keiichi HIRAO, Toshimi YAMANE, Yoritoshi MINAMINO, Toshihiro OKA1991 Volume 41 Issue 3 Pages 197-207
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (1191K) -
Keizo TAKEUCHI, Masami MORI, Takeshi IGUCHI1991 Volume 41 Issue 3 Pages 208-220
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (1815K) -
Nobu SHIOTA1991 Volume 41 Issue 3 Pages 221-223
Published: March 30, 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (289K) -
1991 Volume 41 Issue 3 Pages iv
Published: 1991
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (105K)
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