Aluminum powders were electrodeposited on a tungsten cathode in an electrolytic bath including aluminum trichloride of a major component, separated from the bath by filtering under reduced pressure in the hot molten state, and the bath was cooled. The remained bath was dissolved in agitating ice water. Aluminum powders were recovered by filtering with a cotton cloth and dried at 250°C in an electric furnace. With rising bath temperature or lowering current density, powders are coarsened and their alumina contents are reduced. To produce powders of low alumina content under 2%, aluminum should be electrodeposited at low current density. Aluminum powders with a wide range of desired particle size distribution and aimed alumina content between 1.4% and 30% are produced by this process at the optimum. bath temperature and current density.

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Electrode potential and weight loss of the magnesium alloy (AZ-80A) in alcohols were measured. Continiously measuring the electrode potential against platinum, the magnesium alloy is corroded in methyl, octyl and dodecyl alcohols, 1.2-ethanediol, glycerol and phenol at their boiling points. The alloy is uncorroded in water containing methyl alcohol, but is corroded in another water containing alcohols. The alloy has better corrosion resistance than pure magnesium in alcohols.

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Sliding displacements were measured by use of a square grid marker marked on the surface by vapour deposition of carbon through a mesh of copper (mesh size 25μm). Measurements of the amount of sliding were made for the components parallel to the tensile stress axis, and contribution of grain boundary sliding to total tensile strain was determined as functions of testing temperature and tensile strain. The grain boundary sliding depends strongly on temperature. At 200°C, grain boundary sliding is accompanied by the deformation in a region adjacent to grain boundary. This sliding behavior is closely associated with the serration of grain boundary by localized migration. The contribution of grain boundary sliding shows the maximum at the beginning of tensile deformation and then decreased with increasing strain. At 300°C and above, the amount of migration was more extensive, and alternate sliding and migration are observed. The contribution of grain boundary sliding shows a maximum at a strain of about 10% and then decreased with further increase in strain. The interaction between sliding and migration of grain boundary is important in high temperature deformation of polycrystalline metals.

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Al-4.5% Mg alloys containing Mn 0.3 to 1.0% and ones containing Cr 0.03 to 0.35% were unidirectionally solidified.Mnand Cr refine the dendrite arm spacing. They dissolve to the solid solution and strengthen the alloys, but decrease the elongation and absorbed energy. The alloys containing Mn 0.3% or more or Cr 0.23% or more include intermetallic compounds containing Mn or Cr and have the absorbed energy considerably decreased. The proof stress and UTS of the alloys containing Mn and Cr are increased but the absorbed energy is considerably lowered at-196°C to a greater degree than those at room temperature.

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Brazability of aluminum T-joint (AA 1100) was evaluated by a fillet formation test in vacuum. The crosssection fillet leg length ratio L_V/L_H (L_V: vertical leg length, L_H: horizontal leg length) was used for evaluating the brazability, where the ratio approaches unity under a good brazing condition. A sound fillet can be achieved at the melting temperature range of filler alloys. L_V/L_H reaches a plateau beyond this temperature by isothermal solidification which starts at a fillet edge. Filler alloys containing fine silicon particles are preferable to ensure succesful fillet shape. Iron up to 1.4% in Al-10%Si filler alloy has no influence on the brazability.

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Orthogonal cutting tests of aluminum plates were carried out in such manners as repeated dry cutting, wet cutting, repeated wet cutting and combinations of them under different depths of cut, cutting speeds and rake angles to minimumize the residual stress. In the repeated cutting, the distribution of residual stress in the finally cut surface is considerably influenced by such a cutting condition that leads to high cutting resistance. Both wet and dry cutting result in the same patterns of stress distribution. A combination of dry rough cutting and wet finishing under the adequate cutting conditions ensures the cut surface free from residual stress.

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