After classified by micro- and macro-structures, the parts of the sheet ingots obtained from experiments mentioned in the previous reports was examined on the correlation between the reduction and structures.
The findings are as follows:
(1) Through compression test, it is recognized that the behaviour of the sheet ingot at the time when the reduction is given is related to its micro-structure but not to its macro-structure.
(2) Through examination and statistical study of the relation between grain size in cast structure and recrystallized grain size under the different reduction rates and annealing temperatures, it is recognized that the ingot which has fine micro-structure is rolled into the sheet which has fine grain size.

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The relation between the cooling rate (the average cooling speed from casting temperature of 850°C to the solidifying point) and the degree of super-cooling and the cast structure were studied on the Al-Fe(0.5%) alloy which was cast into various molds.
It is found out that the super-cooling degree ΔT increases with the increase in the cooling rate R, as follows:
ΔT=2R1/3
As the super-cooling and cooling rates increase, the grain size and dendrite cell size get smaller. This phenomenon is more remarkable in the dendrite cell size.

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Aluminium billets (extrusion ingots) of 18mm in diameter and 20 to 80mm in length were "direct-extruded, " with an Amsler type universal testing machine, into rods of 2 to 5.8mm in diameter. From this experiment, the following were found out:
(1) As the extrusion temperature increases, the extrusion pressure decreases. The extrusion pressure goes down as the ram goes, but, regardess of the length of billets the minimum pressure required for extrusion is kept almost constant under the certain temperature and extrusion speed.
(2) The approximate values of the resistance to deformation and coefficient of friction are 4.2 to 10.7kg/mm² and 0.06 to 0.11 respectively. Assuming that the mechanical work done by extrusion is entirely converted into heat which raises the billet temperature, that temperature is to rise by 40 to 110°C.
(3) The increase in the extrusion temperature makes the recrystallized surface layer thicker and the grains coarser.
(4) As the extrusion temperature goes up, the core part of the billet, where the fiber structure is remained, starts to recrystallize in parts.
(5) The longitudinal strength of the front end of the extrusion is more than that of the back end, when extruded at the ram speed of 66 to 123mm/sec and under the temperature of 400 to 500°C. However, inverse is the case of being extruded at 570°C or at 30mm/sec under 500°C. This difference is considered to be resulting from the difference of the cooling rate of each postion of the billet in the container before extruded.

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Immediately after the commencement of rolling operation, the temperature of rolls and other parts of the machine is not so different from room temperature, while, as the operation goes, the temperature naturally goes up. The earing in the process of deep-drawing is different between aluminium sheets rolled under such different conditions as mentioned above, even if they are annealed under same conditions.
Such difference was comparatively examined through analysis by microscopic methode, etching pit and X-ray, respectively.
Through the microscopic analysis, it was found out that the sheet rolled in the later stage of operation is later in the recrystallization and superior in 45°-earing than another. Such difference was recognized more clearly through the other two methods of analysis. The directionality of the sheet rolled in the later stage of operation is superior in 45°-earing than that of the another.

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The reaction between EDDHA and Fe in Al is very sensitive in the pH range of 2-8. Once formed, this red solution is quite stable and its absorbance value is unchangeable over 8 hours.
EDDHA was thus tried to use for the determination of Fe in Al and its alloys and showed the successful results.
The colored Fe-EDDHA chelate compound has a maximum absorption at 470mμ-480mμ.
Through this method, Fe in Al and its alloys is determined in shorter time with excellent accuracy in the co-existance with Mg, Zn, Cr, Mn and Si. In this case, large amount of Cu and or Ti, which interfer the determation, may be removed by electrolysis or masked by EDTA.
Thus, Fe in Al and its alloys can be determined with standard deviation of 0.02%.

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The contraction of aluminium alloy sheets sandwiched in between iron plates under pressure was observed during thermal cycles, and was interpreted in terms of the thermal stress due to the difference of thermal expansion coefficients between iron and aluminium.
The contraction of specimen (Al-0.5at.%Mg alloy) increases as the number of thermal cycles increases, and is dependent on the friction between the specimen and the iron plate and also dependent on the pressure putting upon the specimen. The thermal cycle is such that the specimen is heated up to 200°C and then cooled down. The fractional linear change of specimen during one thermal cycle amounted to 0.15%, being about 60 per cent of the maximum value of 0.24% deduced from the assumption that the dimensional change is caused by the difference of thermal expansion coefficients between iron and aluminium in the course of heating up to 200°C.
It should be noted, however, that no appreciable change in dimensions was observed during thermal cycles provided that the specimen is inserted between aluminium plates. It is, therefore, expected that such dimensional change during thermal cycles could be observed in any case of sandwiched sheets having different thermal expansion coefficients.

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