A new type fabrication process for particles dispersed composites, powder liquid forming technique, was proposed. In this process, first compacts blended of air atomized aluminum alloy powders and ceramic particles were produced by cold press. The obtained compacts were heated up to the melting point of matrix aluminum alloy and pressed in the mold in order to wet between the molten metal and the ceramic particles, and then formed under pressure. The fabrication conditions of this process were investigated mainly from the density and Vickers hardness of Al₂O₃ particles/6061 powder composites. The forming temperature needed over the melting point of matrix and the forming pressure over 80MPa. 0.2% proof stress increased with volume fraction of Al₂O₃ particles. The elastic moudulus of T6 heat treated Al₂O₃ particles/6061 powder composites, E_c, could be expressed as
E_c=178V_f+72(GPa)
where V_f is the volume fraction of particles.

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Aluminum alloy matrix composites containing Al₂O₃ particles were fabricated by powder liquid forming technique. Tensile properties of composites depended on the size of alumina particles, and tensile strength showed 550MPa for 30 wt%Al₂O₃ (d=0.5μm)/6061 aluminum alloy composites. Aging sequence of composites was accelerated by the presence of alumina particles compaired with the matrix alloy. Spinel compounds (MgAl₂O₄) were detected in the Al₂ O₃/6061 aluminum alloy composites heated at high temperature for a long period. Thermal expansion coefficients of 6061 and AC8A alloy composites containing 30wt%Al₂O₃ particles respectively were reduced about 20% compaired with the matrix alloys.

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Precipitation phenomena and mechanical properties in an Al-Li-Cu-Mg-Zr alloy after aging at 150-230°C for various periods were investigated by hardness measurement, tensile test and electron microscopy observation. The thermomechanical treatment have been utilized in order to improve poor ductility of Al-Li base alloys due to intense coplanar slip assosiated with δ' phase. 8 percent rolling reduction prior to aging encouraged the homogeneous precipitation of S' phase within grains, and the widespread presence of S' phase caused the significant improvement in ductility to dispense large planar slip and the increment of strength by additional strengthening effect. More improvement of ductility was not obtained under the condition of higher rolling reduction.

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FeAl₃ intermetallic compounds presented on aluminum matrix are detrimental to surface treatment process of aluminum. An electrochemical method for removing the FeAl₃ from Al-Fe alloy was investigated. The proposed method is cathodic and anodic potentio-dynamical polarization techniques in a certain potential range in Al(NO₃)₃ solution. Appreciable clean surface is obtained by this method.

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A free shape forging process is proposed to make products in different shapes and dimensions by one set of dies and its deformation and load characteristics are investigated in case of applying this process to an axisymmetric hot forging of aluminum. The distinctive feature of this process is that the die configuration is composed of punches applying loads to a specimen individually. In this experiment, the lower die had a rectangular shape in the cross section and the upper die set was composed of three punches of the shapes of two concentric rings and one cylinder, each of which could independently apply a quasi-static load to a specimen. Dimensions of specimen and load were measured during forging, and the maximum load was compared with that of a conventional process. This process of one set of dies has been shown to be able to forge various shapes, and the effect of control procedures of the punches on the deformation pattern is discussed. The maximum load of this process is smaller than that of the compared process. This free shape forging process has been demonstrated to be suitable for making products in various shapes in small quantities.

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Interdiffusion experiments of Al-rich αAl-Cu-Mg alloys have been performed in a temperature range between 753 and 833K. The concentration profiles indicate that the diffusion distance of Mg is somewhat longer than that of Cu in these solid solutions. The diffusion paths show S-shaped curves. The interdiffusion coefficients D^Al_CuCu, D^Al_CuMg, D^Al_MgMg and D^Al_MgCu are positive, and not so sensitive to the solute concentrations. The temperature dependence of D^Al_CuCu, D^Al_CuMg,
D^Al_MgMg and D^Al_MgCu can be expressed by the following equations:
D^Al_CuCu=1.7×10^-5exp(-125kJ•mol^-1/RT)m²/s,
D^Al_CuMg=7.0×10^-3exp(-180kJ•mol^-1/RT)m²/s,
D^Al_MgMg=3.2×10^-5exp(-122kJ•mol^-1/RT)m²/s, and D^Al_MgCu=1.0×10^-2exp(-175kJ•mol^-1/RT)m²/s.
Positive interaction parameters ε^(Cu)_Mg and ε^(Mg)_Cu indicate that Cu and Mg atoms in the Al-Cu-Mg alloys have the repulsive force to each other.

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Tear fracture strength of 5083 aluminum alloy plate was studied experimentally for the test temperatures ranging from 4K to 473K. The total absorbed energy during the tear fracture shows N-letter type changes with respect to the test temperatures indicating the presence of three distinct temperature regions. In the higher and lower temperature regions, the temperature dependences of the total absorbed energy are negative, while they are positive in the medium temperature region. The temperature dependence of the absorbed energy for the crack propagation is substantially the same as that of the total absorbed energy. The total absorbed energy of the specimen L in which the crack propagation direction was vertical to the rolling direction, is higher by about 10 to 20% than that of LT specimen in which the crack propagation direction was parallel to the rolling direction. The tear fracture strength increases linearly with 0.2% proof stress measured by tensile test. No clear linearlity is observed, however, between the ultimate tensile strength and tear fracture strength. A laminated fracture in the tear fractured surface is observed only at 4K.

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There are various processes of strip casting for aluminum and its alloys such as Hunter Eng., 3C, Hazellet and so on. In these processes the melt are poured into the interspace between two rotating rollers or belt. The authors have developed a new strip casting process "Rotary-type continuous casting process". This process has a rotary drum and a fixed metal mold.10mm×420mm and 14mm×420mm strips were produced under following conditions. casting speed: 1-2m/min, casting temperature: 720°C, cooling water: 1.5-4t/hr. Properties of the sheets produced were examined.

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