All issues
Volume 36, Issue 10
Displaying 1-11 of 11 articles from this issue
- |<
- <
- 1
- >
- >|
-
Tsukasa Iwanami1986 Volume 36 Issue 10 Pages 607-608
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (301K) -
Takao CHOH, Takeo OKI1986 Volume 36 Issue 10 Pages 609-615
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe effect of the alloying element on the wettability of graphite to liquid aluminum was investigated by the dipping method instead of the sessile drop method. In the initial stage of the wetting process, there is an incubation period τ which is similar to the wetting process between SiC and liquid aluminum and was decreased by alloying magnesium and IVa and Va group elements in the element periodic table. The wetting process can be analysed from the view point of wetting nucleation rate. The rate constant for wetting, k0, increase by alloying IVa and Va group elements. Both values of k0 and τ have a periodic nature against atomic number of alloying elements. The activation energy for wetting is in the range between 365 and 390kJ/mol for all aluminum alloys and is close to the bonding energy of carbon, 348kJ/mol, given by Pauling. The wetting reaction is limitted by the decomposition of graphite.View full abstractDownload PDF (819K) -
Motohiro KANNO, Hisashi SUZUKI, Kazuhiro ITOI1986 Volume 36 Issue 10 Pages 616-621
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSAging phenomena of an Al-4%Cu-1.6%Mg alloy with 0.17%Zr were studied in comparison with those of Al-4%Cu-1.6%Mg alloys with and without 0.60%Mn. Homogenized specimens were worked, solution-treated, quenched and naturally or artificilly aged at 200°C. Interrupted quenching followed by artificial aging was also adopted. Dislocation loop structures of the ternary alloy is slightly modified by zirconium addition both in natural and artificial aging, this being in contrast to the case of manganese addition where no dislocation loop is observed in artificial aging. Consequently, age-hardening behavior of Zr-bearing alloy is similar to that of the ternary alloy in artificial aging, and their maximum hardness values became a little smaller than that of Mn-bearing alloy. Quench-sensitivity is lower in Zr-bearing alloy than in Mn-bearing alloy. Coherent dispersoids formed in Zr-bearing alloy never act as heterogeneous precipitation sites for S-phase during interrupted quenching.View full abstractDownload PDF (1845K) -
Takeshi HATTORI, Shigeo SAKAI, Yukihiro SAKAGUCHI1986 Volume 36 Issue 10 Pages 622-626
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSAn accelerated simulation corrosion test of aluminum alloys in salty atmosphere was developed. The corrosion resistance of aluminum heat exchangers of car air-conditioners was evaluated. A relation of pitting corrosion behavior of aluminum heat exchangers between the simulation test and a partical test in Okinawa Island was clarified. The crrosion life of aluminum heat exchangers can be evaluated by the lavoratory corrosion test.View full abstractDownload PDF (476K) -
Tadashi TAKEMOTO, Hideyuki NAKAMURA, Ikuo OKAMOTO1986 Volume 36 Issue 10 Pages 627-632
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSVacuum brazing of titanium with various aluminum filler metals was performed to investigate the clearance filling ability, formation of Al-Ti intermetallics and joint strength. Fully filled clearance length is obtained on brazing at 680°C for 3min irrespective to composition. However, the thickness of intermetallic compound layer is greatly different by the filler metal composition. The maximun layer thickness is observed in 99.99% high pure aluminum. All additional elements surpress the layer thickness. Addition of 0.8%Si extremely reduce the layer thickness. Intermetallic compounds of pure aluminum and Al-0.1-0.8%Si filler metals are Al3Ti. Joint strength is almost equal in both filler metals after low temperature and short time brazing (680°C, 3min). Brazed joints made by Si bearing filler metals maintain high strength after high temperature and long time brazing, whereas joint strength with pure aluminum is remarkably low.View full abstractDownload PDF (1328K) -
Masataka MASUDA, Susumu NANAO, Noboru MASUKO, Takashi MOCHIZUKI1986 Volume 36 Issue 10 Pages 633-639
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSTo improve an electrical capability of aluminum electrolytic capacitor, a new electrode material of large dielectric constant and high dielectric strength. This thin film electrode of titanium rich aluminum alloy is made with a rapid quench method and has very small grain size of a few micrometers and high toughness. Al-Ti alloy capacitors of this thin film show CV value of 1.5 times as large as an uptodate aluminum capacitor. Characteristics of chemical formation and etching of the Al-Ti alloy electrode is referred.View full abstractDownload PDF (1021K) -
Yoichi TOMII, Masao KIKUCHI, Masao MIZUNO1986 Volume 36 Issue 10 Pages 640-646
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSA study was made on the aging behavior in a resistance spot weld of commercial Al-Zn-Mg alloys. Hardness measurements, X-ray small-angle scattering method and electron probe X-ray microanalysis were applied. The hardness increases not so much in the nugget as in the heat affected zone by post-weld aging at room or elevated temperatures. The hardness in the nugget increase with an increase in distance from the nugget center at any aging times and temperatures. Softened zone is observed in the heat affected zone near the fusion line by post-weld aging. These aging characteristics are also found in the resistance spot weld aged after solution treating for 1h at 465°C. The X-ray integrated intensity is always lower for the nugget center than for the heat affected zone during the aging after welding or after solution treatment. These results are attributed to the fact that there exist macro- and micro-segregations of solute atoms in the nugget of the resistance spot weld of commercial Al-Zn-Mg alloy.View full abstractDownload PDF (1283K) -
Tadakazu OHNISHI, Hideaki SHIOTA1986 Volume 36 Issue 10 Pages 647-656
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSA three-step aging process to reduce the susceptibility of 7475 aluminum alloy to stress corrosion cracking, and to keep high strength, was investigated. This process includes the first low temperature aging, the second retrogression at higher temperatures, and the third reaping at low temperature once again. For the condition applied to the first step the usual T6 treatment is most suitable. For the second step the higher the retrogression temperature was adopted and the longer the time is done, the lower the susceptibility is effected, although a complete recovery to the original T6 strength level is only found in the time region up to about the minimum in the retrogression curve, and in longer time the strength is gradually decreases. For the final reaging the usual T6 treatment is suitable. The maintenance of high strength and improvement of susceptibility may be attributed to different effects of the process on the precipitation structure of innergrains and of grain boundary. The fine precipitation structure of innergrains which is kept by reversion and reprecipitation may serve to hold high strength, while the coarse grain boundary structure formed by growth of precipitates may sreve to improve the susceptibility.View full abstractDownload PDF (2038K) -
Kenzo KOBAYASHI, Kenichi SHIMIZU, Toru OHYA1986 Volume 36 Issue 10 Pages 657-659
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (730K) -
Yoich TOMII, Masao MIZUNO1986 Volume 36 Issue 10 Pages 660-672
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (1713K) -
Yoshikuni KAWABE1986 Volume 36 Issue 10 Pages 673-681
Published: October 31, 1986
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (1171K)
- |<
- <
- 1
- >
- >|