It has been required for long years to produce aluminum coating of abrasion resistant oxide film. However, in the conventional process, abrasion resistant oxide layer was produced only by anodizing in electrolyte at low temperatures, or in the range of -10-0°C. Such process had disadvantages for setting up expensive refrigerating plant in order to maintain the low temperature.
This report relates to the hard anodizing of aluminum in the electrolytes of sulfuric acid-dicarboxylic acids, whereby efficiency of the formation of oxide film, and hardness and abrasion resistance of the film were improved.
The most excellent results were obtained with the electrolyte containing 15% (by wt.) of sulfuric acid+1-5% (by wt.) of malonic acid. The film produced with the above electrolyte at 20°C had almost so high impact abrasion resistance as that produced with the electrolyte of 15% (by wt.) of sulfuric acid alone at 5°C.
The above mixed electrolyte could be operated at temperature of about 10°C higher than the case of sulfuric acid alone and no reduction of abrasion resistance was observed. The results of this study dissolved the problem of disposing of refrigerating plant.

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Electrolytic grinding process has remarkable effects on the grinding of hard to grind materials such as cemented carbide, superalloy, etc. However, it would be important to find out various operating conditions for giving the most remarkable effects.
Several experiments for electrolytic grinding of cemented carbide carried out for determining optimum conditions are reported in this paper.
Some of the results obtained are as follows.
(1) The rate of stock removal increased in linear proportion to current density, and current density decreased with the increase of d.c. voltage.
(2) The range of d.c. voltage controlling the mechanical grinding action was determined by microphotographs of electrolytically ground surfaces.
(3) The optimum conditions relating to d.c. voltage and working pressure were accurately expressed by the power consumption of the spindle motor.

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The structure of nickel crystals electrodeposited under low current density on (110) plane of copper, which had been etched with aq. solution of ammonium persulfate, was observed with electron diffraction and electron microscope.
When the deposited layer was thin, it was observed that the growth of the nickel deposit conformed upon the orientation of the substrate metal, and twin crystallization was repeated on {111} faces.
When the deposited layer was thick, it was observed that crystals of similar figures were distributed with regular orientations, and all of the surfaces were constituted by projections consisting of {111} faces.

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Variation of Stress in the layer painted with a polystyrene-benzene solution on a plane surface of rigid body was measured.
The tensile stress appeared in the layer immediately after painting and its intensity gradually increased with the lapse of time and asymptotically approached to a definite value between 60 and 100kg·cm^-2.

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