An addition of chromium to magnesium alloys containing aluminium was tried by preparing a mother alloy with aluminium, and corrosion test was carried out in N/10 NaCl solution.
It is shown that the addition of chromium for magnesium alloys containing aluminium, but not manganese, is markedly effective as that of manganese to reduce the rate of corrosion (Mg-Al-Zn-Cr alloys prepared with mother alloy Al-Zn-Cr containing 10-25% Cr, Table 2 and Fig. 2), but for magnesium alloys containing both aluminium and manganese it has no effect (Mg-Al-Mn-Cr alloys prepared with mother alloy Al-Mn-Cr containing 5-15% Cr, Table 1 and Fig. 1), or it is slightly effective (Mg-Al-Zn-Mn-Cr alloys containing more than 0.2% Mn which were prepared with mother alloy Al-Zn-Mn-Cr containing 5-25% Cr, Table 3 and Fig. 3).
All alloys thus prepared, however, lost a large amount of chromium in melting, and found to contain only 0.01-0.03% Cr by analysis, irrespective of chromium content in mother alloys used and hence whether the beneficial effect is brought about by chromium addition or not is somewhat obscure.
The effect of Sn, Cd, Pb, Ca, Sb, Bi, Si, Ce, Se, Ba, Mo, V or Zr added to Electron AZG alloy, containing small amount of chromium as above, has also been studied. The results obtained are shown in Fig. 4 and in Table 5 and 6.

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The problems on melting, casting, forging, change of mechanical properties due to heat treatments and microstructures of 42 kinds of copper base alloys containing 20 per cent of Fe were investigated, and the following results were obtained.
(1) The fluidity of melts added by Al was good, and sound and smooth surface castings were obtained by pouring then into a Durville type casting mould although dross was liable to be formed on the surface of the melts. On the contrary, melts containing Si but no Al were viscous, and liable to form gas bubbles in the castings, the formation of which was prevented by using CaF₂-NaCl flux. In melting alloys containing Si and Al, a small amount of dross and fairly sound ingots were obtained.
(2) The primary crystal rich in Fe of alloys containing Cr was apt to become massy particle, and alloys containing Sn or P have shown the tendency to promote the segregation of the primary Fe-rich phase.
The alloys containing Al and Si, say No. 19 alloy, have shown uniform and fine structures. The simultaneous addition of Al-Mn, Al-Ag or Si-Ag to Cu-Fe alloys does not cause to refine the crystal grains of the alloys.
(3) The forgeability of alloys consisted of only two phases rich in Fe or in Cu was good in general. But alloys containing Sn could not be forged due to the formation of a third constituent.
The forging of Cr-containing alloys was difficult. The formation of forging cracks is considered to be due principally to the segregation of the primary Fe-rich crystal of massy particles.
It is the necessary treatment for Si-containing melt to wash it with fluxes and remove the absorbed gases in order to render forging of the castings easy.
(4) The mechanical properties of the alloys were not improved by heat treatments, except 0.6% Be-1.0% Ni-20% Fe-bal. Cu alloy, in which Ni is the necessary element to give the age-hardening property of the alloy in the existence of Be. The age-hardening of this alloy is considered to be due principally to the solubility change of Cu-rich solid solution forming the matrix of the structure.

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In the course of investigation of Copper-Nickel-Beryllium alloys some questions were found to be elucidated in the equilibrium diagram of the Nickel-Beryllium system, and hence the author studied nickel-rich alloys of this system by means of thermal, magnetic, X-ray analysis as well as microscopic observation and the hardness measurements.
The general view of the diagram, as is shown in Fig. 8, which is obtained by the author, well coincides with the diagram shown by Masing-Dahl, but in detail the following new points were clarified by this experiment.
(1) The compound Ni₅Be₂, which was said to exist by Misch from his X-ray investigation, does not exist in any range of temperatures in this system.
(2) The two phases forming the heterogeneous structure in the alloys ranging from 1 to 13 per cent. Beryllium are α and β, and none others. The β-phase is a solid solution based probably on NiBe, its solid solubility of Nickel being lange at high temperatures and decreasing considerably with lowering temperature.
(3) The α-phase contains less than 1 per cent. Beryllium in solid solution at room temperature. The amounts of Beryllium contained in the α-solid solution are about 2 per cent. at 900°, 2.6 per cent. at 1000° and 2.8 per cent. at 1100°.
(4) The Curie point of α-phase saturated with Beryllium at room temperature lies at 255°. The supersaturated α-phase with 2.7 per cent. Beryllium at room temperature shows the Curie point at about 90°.

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The authors performing some experiments on extruded super duralumin, found a peculiar micro-structure, which has given a speculation that the excellent mechanical properties of extruded rod is attributed to particular working process.
To study the cause of excellent properties due to extrusion several examinations were performed, as follows.
1) Crystal flow in the course of extruding process.
2) Relation between mechanical properties of extruded rod and its degree of deformation by areal reduction in extruding work.
3) Orientation of mechanical properties by extruded rod.
4) Influence of preceding forging on the billet of extruding rod.

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The crystalline configurations of a few specimens of white tin, deposited electrolytically from the solutions containing a small quantity of Fe⁺⁺, Mn⁺⁺ and Cu⁺⁺ ions respectively in addition to Sn⁺⁺ or Sn⁺⁺⁺⁺ ions were investigated with X-rays. Supplementary to these specimens, the inner structures of various electrolytic specimens of alloys belonging to Zn-Cu and Ni-Ag systems were also examined. By comparing the experimental results thus obtained with those of our previous researches⁽¹⁾, carried out mainly utilizing some stannous or stannic solutions free from any foreign metallic ions, we arrived at the following conclusions:-
(1) The micro-crystals of white tin have a tendency to arrange themselves in the electrolytic specimens, deposited from the solutions containing Mn⁺⁺ or Cu⁺⁺ ions besides Sn⁺⁺ or Sn⁺⁺⁺⁺ ions, with the normals to their (101) faces⁽²⁾ parallel to a definite common direction, as was the case in our previous researches: But, with the specimens coming to appear from the solutions containing a small quantity of Fe⁺⁺ ions besides Sn⁺⁺ ions, this direction of the common axis was observed usually to coincide with the normals to (100) faces of the micro-crystals of white tin.
(2) The presence of Fe⁺⁺ or Mn⁺⁺ ions in addition to Sn⁺⁺ ions in the electrolyte, not only converts the direction of the maximum growth of the deposited tin, in the way similar to the case of the alternation of the ionic valency of Sn, but also affects to some geometrical properties previously found with the electrolytic specimens of white tin.
(3) As the consequence of the experiment carried out with the specimens of alloys belonging to Cu-Sn system, it can be concluded on the one hand, that some electrolytic depositions containing two kinds of metals are nothing but an aggregation of crystals of one of these constituents, the other constituent being supposed to exist mostly outside of the aforesaid crystals in a colloidal state. But, on the other hand, the experimental results obtained with the specimens of alloys belonging to Zn-Cu system, show us that the crystal lattices in accordance with the phase diagrams of alloys, may also be formed by the procedure of electrolysis, as was previously suggested. (3) (4)
(4) The increase of the solubility range between the constituents of alloys, which has already been found by numerous investigators (3) (4), is confirmed not always to be detectable at least in the case of the alloy belonging to NiAg system.
The facts summarized above, seem to give some clues to the considerations, on the effects of foreign metallic ions upon the inner structures of metals and alloys prepared by the procedure of electrolysis.

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