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Volume 31, Issue 4
Displaying 1-10 of 10 articles from this issue
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Kanji TAKEUCHI1981 Volume 31 Issue 4 Pages 217-218
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
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Tetsuya TAKAAI, Takanori HAGIHARA, Tran Van THANG1981 Volume 31 Issue 4 Pages 219-225
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSYield strength and hardness of the 5083 sheet annealed at 520°C especially for 2000min or more are considerably lowered. The surface and interior portion of the sheets annealed for 4000 and 14400min have substantially different hardness. The fact is attributed to difference in Mg concentration resulted from vaporization of Mg. An intermetallic compound Mg2Si remarkably decreases during prolonged annealing for 4000min or more. Another intermetallic compounds composed of Al, Fe, Mn, Cr and Si relatively increase with respect to decrease of Mg2Si. Initial Mg content 4.59wt% reduces. down to 0.26wt% by annealing for 14400min.View full abstractDownload PDF (1338K) -
Yasuhisa TOZAWA, Takashi KATO, Naoyuki KANETAKE, Kenji KOJIMA1981 Volume 31 Issue 4 Pages 226-231
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe average texture over thickness was measured by the Schulz reflection method for determining one quadrant of pole figure of aluminum sheet 1100-H14. The texture measured is represented by a three-dimensional orientation distribution function. Yield locus and r-value are calculated using the theory developed by Bishop and Hill, in which an orientation distribution function is used as a volume fraction of certain orientated crystals. A chain of the measurement and calculations is executed by the micro- and large-computer 'quasi-on-line'. The calculated yield locus is close in shape to that measured by the biaxial compression test except a deviation based on Bauschinger effect. The calculated directional variations of stress in some strain or stress states and of r-value are in good agreement with observed ones.View full abstractDownload PDF (735K) -
Hisashi SUZUKI, Motohiro KANNO, Goroh ITOH1981 Volume 31 Issue 4 Pages 232-239
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe aging behavior of Al-(0.7-1.1)at%Mg-0.4at%Ge alloys subjected to normal aging and two-step aging was studied comparing with the previous results of Al-Mg-Si alloys. Nearly the same behavior as in the Al-Mg-Si alloy is found: (α+Mg2Ge) two phase alloy shows a following erecipitation sequence, solid solution →cluster→needle-shaped G.P. zone→rod-shaped intermediate phase→cube-shaped intermediate phase→plateshaped equilibrium phase; the alloy attain a maximum hardness in the state of G.P. zones. The maximum hardness value of the alloy step-aged (pre-aged at 20-150°C and finally aged at 175°C) is always lower than that normally aged. The negative effect of two-step aging is more marked in this alloy system. Discussions on the difference of the negative effect between both systems are given.View full abstractDownload PDF (2085K) -
Hajime KATO, Tatsumi TOZAWA1981 Volume 31 Issue 4 Pages 240-247
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSRotary-bending stress fatigue tests were carried out on Mg, AZ31 and AZ61 alloys. Mg, AZ31 and AZ61 have fatigue strengths in this order. They have ratios of bending stress to tensile strength at 107 cycles about 0.15, 0.32 and 0.29 respectively. The relationship between crack propagation rate and stress intensity factor is expressed as: da/dN=C(Kmax)m, where m and C are constants. The value of m is 4 for Mg and AZ31 and 3 for AZ61. The crack propagation rate of AZ31 is some one-tenth as much as that of Mg. The crack in AZ31 runs zigzag in the early stage and propagates nearly normal to the stress direction accompanying a distinct plastic zone. The fractograph of AZ31 changes from cleavage-like fracture mode to the fracture mode by striations with cracks propagated.View full abstractDownload PDF (1988K) -
Toshiro KOBAYASHI, Eiji KATO, Nobuhiro SHIMIZU, Yoshisada UEDA1981 Volume 31 Issue 4 Pages 248-254
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe valid JId value is measurable using deeply notched Charpy specimens. The value of 7N01 alloy depends on the heat treatment condition. Over aging results in the high value. The peak aged and 2-step aged 7N01 and 2017 alloys have rather low level of the toughness value. The apparent Jd is affected by the notch root radious and by the microstructure. UPE values obtained in the tear test have a good correlation with the fracture toughness KId. The fracture propagation resistance (R-curve) corresponds to the dynamic fracture toughness value. The rank of toughness is in the order of 5083, 7N01 and 2017. Use of the 1/2" thick static three-point bend specimen never permits the valid KIc value.View full abstractDownload PDF (1149K) -
Kensuke KURIHARA, Tatsumi TOZAWA, Hajime KATO1981 Volume 31 Issue 4 Pages 255-260
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe tool-workpiece thermocouple method (Gottwein's method) was applied for measuring the cutting temperature of Mg and AZ31 and AZ80 alloys. The cutting conditions were; cutting speed 400 to 2200m/min, feed 0.06 to 0.65mm/rev and cutting depth 3 and 5mm. The highest cutting temperatures of 480°, 520° and 530°C are attained at the cutting speed 2000m/min for Mg, AZ31 and AZ80 respectively. The practical cutting condition is discussed on the basis of the isothermal curves on the cutting speed-feed diagram with respect to the present extremely high turning speed for Mg. The cutting temperature is below about 400°C.View full abstractDownload PDF (1103K) -
Mototsugu KATSUTA, Ken-ichiro AOKI, Shiro KOHARA1981 Volume 31 Issue 4 Pages 261-265
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSCharacteristic parameters for plastic deformation and textures of 1050-H18 aluminum sheets annealed at various temperatures were determined. When only recovery occurs at low annealing temperatures the limit strain slightly increases. When recrystallization occurs at elevated annealing temperatures, the limit strain remarkably increases. The limit strain is, however, not so affected by grain growth. The variation in the limit strain well corresponds to variation in the n-value of annealed sheets. Variation in the r-value has less effect on the limit strain than the n-value. The texture has no difinite effect.View full abstractDownload PDF (591K) -
Teruo KISHI1981 Volume 31 Issue 4 Pages 266-276
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
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Hisashi SUZUKI, Motohiro KANNO1981 Volume 31 Issue 4 Pages 277-298
Published: April 30, 1981
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (3641K)
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