Powder of carbides such as TiC, TiC-WC, TaC-WC, and WC was added to pure (99.99%) aluminum. The mixture of Ti-salts (K₂TiF₆+Na₂TiF₆) or chiolite was also added as a flux to prevent the oxidation of carbide and molten metal. The molten metal containing the carbide was held at above melting point for a period. After slow solidification in a crucible, the grain size of the specimen was determined.
The results were summarized as follows:
(1) TiC, TiC-WC, and TaC-WC were very effective for the grain refining of pure aluminum. The effects of refining of these carbides were almost kept constant and the size of grains was not coarser after the molten metal was held at such a high temperature.
(2) WC had less effects on the refining as compared with other carbides, and it was difficult to get a homogeneous specimen by mixing WC into aluminum.
(3) Chiolite was a very favorable salt for promoting the production of homogeneous specimens consisting of aluminum and carbide.
(4) The addition of hexachlorethane showed no change in the grain size of aluminum containing titanium.

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In the previous paper, the effects of various additional elements on the galvanic anode properties of aluminum and its alloys were reported.
The authors pointed out that the addition of Hg was the most effective. The alloys containing 0.05% of Hg showed anode potential of -1.00-1.05V and current efficiency of 90-95%. However, the corrosion of Al-Hg alloys was not uniform.
The present study was made for the purpose of improving Al-Hg alloys.
(1) Addition of Pb to Al-Hg-Zn alloys improved the corrosion state.
(2) Among Al-Hg alloys, Al-Hg-Zn-Pb alloys showed anode potential of -1.10-1.15V and current efficiency of 90%.
Furthermore, the corrosion on these alloys were apt to be uniformily dissolved and did not make the corrosion product adhere to the specimen.
(3) Al-Hg alloys showed low potential and high current efficiency under the anodic current density of 0.2-6.0mA/cm².
(4) The anode potential of Al-Hg alloys, especially Al-Hg-Zn-Pb alloys, was maintained at low values for 1, 000hr.

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It was found that the color tone of anodized films on Al-Mn or Al-Mn-Mg alloys were sensitively changed in accordance with the conditions of heat treatments of mother alloys before anodizing. The relationship of the heat treatments before and after working to the color tone of anodized film was investigated, and the following results were obtained.
1) When Al-Mn-alloys were precipitation heat treated at about 400°C before or after working, and then anodized, the color tone of the films was black.
2) The color tone of anodized films was sensitively changed according to the temperature of heat treatment. It was uniformly grayed when the alloys were treated at about 550°C.
3) The color tone of the films was deep black, when they were sealed in boiling distilled water.
4) The color tone of the films was changed to brown by the addition of Si. It was slightly changed to brown by the addition of Fe, but showed no change by Mg. Color streaks were often evident on anodized films of Al-Mn alloys (especially, on rolled plates). However, the streaks can be prevented by the addition of Mg to the alloys.

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These studies were carried out for the specimens of pure aluminum wire (purity 99.99%) to discuss the variations in tensile strength, clongation. hardness, crystal structure, etc. according to the temperatures of cold drawing and annealing.
The results obtained were as follows:
(1) The tensile strength increased linearly with the increase of the degree of reduction and it attained to a maximum value of 12-13kg/mm².
(2) The distribution of the hardness of cold drawn specimens was nearly uniform in the case of lower reduction degree; on the other hand, when the reduction degree was above 60%, the hardness was low on the surface, but high in the centre of the specimens.
(3) The annealing temperature giving the maximum elongation was 250-300°C. for the specimens of the reduction degree of above 80%. The grain size of the specimens at that temperature was very uniform within the range of 0.08-0.1mm.

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Drilling and reaming tests were conducted to discuss the machinability in cutting resistance, working time, accuracy in the size of worked hole, etc. on modified high silicon aluminum cast alloy, called "Alusil."
The results showed that drilling resistance, in particular, thrust was extraordinarily high in Alusil, and the constant load required for drilling of Alusil was much greater as compared with that of general wrought aluminum alloys or no modified aluminum-silicon cast alloys. The drilling resistance was higher in heat-treated material than in as cast, and the resistance of the material in graphite mould was higher than that of the material in metallic mould. There was found a reciprocal relation between the torque and the drilling time under constant load and the above relation agreed with the results of the experiments in the past.
On the other hand, in reaming of Alusil, the thrust was rather small and the torque was very large. Also, in this case, the reaming resistance was higher in heat-treated material than in as cast, and the resistance of the material in graphite mould was higher than that of the material in metallic mould. The diameter of reamed hole was fairly larger than that of reamer, and the distortion in the size of the hole diameter was of ten recognized. However, the above distortion in heat-treated material was smaller than that in as cast material.

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