軽金属
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
40 巻, 2 号
選択された号の論文の14件中1~14を表示しています
  • 牧 清二郎, 中村 雅勇
    1990 年 40 巻 2 号 p. 75-81
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    Joining of aluminum (A1100) and four kinds of ceramics, Si3N4, SiC, Al2O3 and PS-ZrO2 (partially stabilized), was attempted by using Al-Mg and Al-Si alloys as fusible insert. Effects of insert composition and joining parameters, such as temperature, time, pressure, cooling rate and amount of insert, on the bond strength were investigated. The results obtained are as follows: (1) Both aluminum alloys worked successfully on the joining, and relatively high bond strength was obtained at the compositions, 5-20wt%Mg and 5-10wt%Si. (2) Joining at temperatures below 878K using the Al-Mg alloy insert, however, gave rise to high thermal stress, which decreased the bond strengths of Al2O3 and SiC remarkably. (3) A use of Al-Si alloy insert can be recommended when thermal stress becomes a serious problem. (4) Al-10wt%Mg alloy can be recommended as suitable insert for Si3N4 and SiC, and Al-5wt%Si alloy for PS-ZrO2 and Al2O3. (5) The following measures are effective to reduce the thermal stress in use of the Al-Mg alloy insert; i) to minimize the amount of the insert, ii) to increase joining temperature and/or time, and iii) to decrease the rate of cooling after joining.
  • 大西 忠一, 茨木 良昭
    1990 年 40 巻 2 号 p. 82-87
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    The RRA (retrogression and re-aging) process was investigated in order to reduce the susceptibility of 7075 aluminum alloy to stress corrosion cracking, and to keep high strength due to T6. The process includes the first low temperature aging, the second retrogression at higher temperature, and the third re-aging at low temperature. For the first aging the usual T6 treatment is practically suitable. For the second retrogression the higher the temperature is adopted and the longer the time is done, the lower the susceptibility is effected, although the strength decreases in the case of over-aging of the retrogression. For the third re-aging it is preferable to increase the temperature and the time to an extent within the permissible range of loss in strength. These effects can be explained by taking account of the different influence of the RRA process on the structure of precipitates within grains or at grain boundaries.
  • 足立 勝重, 新井 典久, 井垣 久, 小川 恒一
    1990 年 40 巻 2 号 p. 88-94
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    The cutting characteristics of aluminum by frequency vibratory drilling were examined compairing with those of conventional drilling. The application of this method to drilling of soft material such as pure aluminum was more effective than that of the conventional drilling from the standpoint of chip control, work strain and machined surface layer.
  • 市村 稔, 篠嶋 妥, 今林 守
    1990 年 40 巻 2 号 p. 95-101
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    Hydrogen diffusivity D(m2s-1) in the ingot of Al-(0-50mass%)Cu alloys were measured for ND-samples solidified unidirectionally in pure nitrogen gas fllow. The Arrhenius type dependence of D on temperature is realized above about 400°C, but an upward departure is noted below 400°C. In the region of α-solid solution (Cu<5.7mass%), D decreases with the addition of copper. In the coexistent region of primary and eutectic crystals (5.7<Cu mass%<52.6), D is controlled by the following two factors, (1) an enhanced diffusion of hydrogen along the interface between primary and/or eutectic crystals and (2) a suppressed diffusion by hydrogen trapping at eutectic-lamellae interfaces. The value of D for θ-phase is a little greater than that for α-solid solution with 5.7mass%Cu. For AM samples melted in air, D is clearly smaller than that of ND or VM samples melted in vacuum with no voids. The Arrhenius type plots D=D0exp (-Q/RT) above 400°C have yielded a linear relationship between log D0(m2s-1) and Q(kJ•mol-1), namely D0=2.22×10-8 exp (0.138Q).
  • 山田 始, 田中 他喜男
    1990 年 40 巻 2 号 p. 102-108
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    Effects of Fe on the recrystallization behavior, resultant grains and their growth in Al-1mass%Mg alloys and in Al-1 mass%Mg-0.6mass%Si alloys, both of which contain small amounts of Fe (0.07-0.4%) as an impurity, were studied. Recrystallization of high purity Al-Mg alloy is hardly affected by homogenizing conditions for ingots. While, its recrystallization is significantly accelerated or retarded depending on the homogenizing temperatures when containing more than about 0.1mass%Fe. In Al-Mg-Si alloy, its recrystallization is remarkably affected by homogenizing temperatures independently of existence of Fe. Fe also effectively works for generation of recrystallized grains in these two alloys. Furthermore, Fe has a significant retarding effect on the grain growth, and grain coarsening in these alloys at elevated temperatures is effectively prevented by contained Fe.
  • 今井 克哉, 米谷 茂
    1990 年 40 巻 2 号 p. 109-115
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    Residual stresses in the aluminum sheet specimens rolled from 20 to 89% total sectional reduction were measured. Used reduction per pass was 20% and more heavy percentage. Textures in the sections of these specimens were measured. Normal residual stress generated to the rolling direction is tension in the outer parts and compression in the inner parts of these specimens except heavily reduced ones. In the residual stress distribution of these specimens, the layer where the residual stress changes from tensile to compressed one corresponds to the layer where hardness begins to decrease slightly in the inner part. It has been shown that these residual stresses are correlated with the texture formed by the rolling, and that residual shearing stress in the section has the relation to the structural internal strain caused by the plastic deformation.
  • 張 荻, 佐治 重興, 藤谷 渉, 堀 茂徳
    1990 年 40 巻 2 号 p. 116-122
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    Composite precipitates consisting of the core particle, presumably Al3 (Li, Ti) and the outer shell of δ'-Al3Li phase were formed by a two-stage aging(at 500°C and then at 180 or 190°C) in chill cast specimens of Al-(1.6-2.3) wt% Li-(0.45-0.95) wt%Ti alloys. Al-Li-Ti ternary alloys containing both the composite precipitates and δ' particles in the peak-aged condition, showed a considerably superior ductility to that of the peak-aged Al-Li binary alloy together with a higher strength. Bow-out dislocations and tangled dislocations were observed near the composite precipitates in the tensile-strained specimens of Al-Li-Ti alloys and shear type of transgranular fracture were recognized in SEM fractography of the peak-aged specimens of Al-Li-Ti alloys containing the composite precipitates, whereas planar slip of dislocations and typical intergranular fracture were observed in the peak-aged specimens of Al-Li binary alloys. The composite precipitates improve ductility by retarding the planar slip mode in Al-Li-Ti alloys.
  • 樋野 治道, 小松 幹也, 森 博太郎
    1990 年 40 巻 2 号 p. 123-130
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    In order to improve the high temperature properties of an alumina short fiber reinforced magnesium alloy for automotive component application, an alumina short fiber reinforced Mg-Nd alloy, referred here to FRMg, has been developed by squeeze casting. The relation between its properties and metallurgical structure has been examined with the following experimental results. (1) The high temperature strength of FRMg with a sound metalluegical structure is superior to that of the matrix. (2) Mg2Si precipitate produced by the reaction between the molten magnesium metal and silica binder in the fiber preform is preferentially present in the area where the molten magnesium metal finally infiltrates. (3) In the deformation of FRMg containing Mg2Si precipitates, the fracture of Mg2Si precipitates in contact with the fiber is observed in the heavily deformed matrix. (4) The properties of FRMg containing Mg2Si precipitates scatter considerably, with some of them being inferior to those of the matrix. Examination of the metallurgical structure reveals, in the FRMg containing Mg2Si precipitates, that Mg2Si fractures at the beginning stage of plastic deformation because of the stress concentration induced at the precipitate/matrix interface and that this degrades the properties of FRMg.
  • 井上 哲雄, 沖 猛雄
    1990 年 40 巻 2 号 p. 131-137
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    The effect of surface roughness of Al-Zn-Mg alloy on passivation and corrosion behaviors was investigated by measuring anodic polarization curves in 0.5N NaCl solution. It is shown that pitting potential tends to shift less noble and passivation current density increases with increase of surface roughness. It is found thet there is a border line for the surface roughness (Rmax) between 5 and 10μm where the pitting potential and the passivation current density change sharply in 0.5N NaCl solution. It is considered from the results of polarization behavior that the pitting corrosion resistance of a passivation film on a specimen decreases remarkably at the surface roughness beyond 30μm.
  • 土公 武宜, 浅見 重則, 石川 和徳
    1990 年 40 巻 2 号 p. 138-144
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
    3003 alloy bare fins, the basic component for brazing application, were made with varying distribution of precipitates and amount of solution by changing homogenizing conditions and with varing strain by changing the final reduction ratio of cold rolling. These fins were submitted to a sag test, and the change in sag distance was investigated in relation to the structural change during heating. The sag is classified into two components; one is controlled by recovery and recrystallization and the other occurs in the temperature range 550-610°C without structural change after the completion of recrystallization. The former component occurs accompanied by the migration of dislocation and grain boundary. Thus, in the case where the driving force for recrystallization is small and the dragging force is large, the sag tends to be large as the recrystallization during heating continues to the elevated temperature, making the migration of dislocation and grain boundary easy. The latter component which advances without structural change is caused by creep. Therefore, when the driving force is large and the dragging force is small, grain size becomes smaller, leading to a larger sag.
  • アルミニウム粉末冶金研究組合 , 武田 義信
    1990 年 40 巻 2 号 p. 145-155
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
  • 松井 邦昭
    1990 年 40 巻 2 号 p. 156-168
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
  • 井野 博満
    1990 年 40 巻 2 号 p. 169-170
    発行日: 1990/02/28
    公開日: 2008/10/30
    ジャーナル フリー
  • 1990 年 40 巻 2 号 p. v
    発行日: 1990年
    公開日: 2008/10/30
    ジャーナル フリー
feedback
Top