Orientational dependence of morphology of anodic oxide film on grain orientation was investigated by the micro-focus X-ray diffraction technique. It was found that the shape of oxide film changes depending upon grain orientation and striations are formed parallel to the trace of <100> direction of the substrate when its surface is nearly parallel to {110}. The striations can be made use of as a help to distinguish between cube grains and grains in the {110} (hhl) orientation in rolled and annealed aluminum with strong recrystallization texture. It was also shown that the striations are useful to reveal the orientation change or local curvature in the banded structure of aluminum single crystals rolled to (014)[100] and (001)[110] orientation.

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Precipitation phenomena in the weld metal of an Al-5.8%Zn-1.2%Mg alloy during cooling after welding were studied by means of hardness measurements, X-ray small angle scattering methods and transmission electron microscopic observations. It was found that there existed G. P. zones and the equilibrium phases in the weld metal immediately after welding. These precipitates were considered to be formed during cooling after solidification. It was also found that the existence of these precipitates affected the aging characteristics of the weld metal after welding.

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This study was carried out to determine the effect of grain size and number of primary silicon crystals on the machinability of hypereutectic Al-Si alloys. The results obtained are as follows:
(1) The effect of grain size, d (mm), and number, n (No./mm²) of primary silicon crystals on the flank wear of the tool, V_B(mm), are represented by the form, (d^2.50⋅n)^m. The value of exponent m is as follows.
Sinterd carbide tool;
(VB_??_0.2mm)m=0.68, (V_B0.2mm)m=0.58
High speed steel tool; (VB>0.3mm)m=0.58
Therefore, refinement of primary silicon in hypereutectic Al-Si alloy is very effective in decreasing the tool wear.
(2) It is found that the cutting force is inversely proportional to d^0.5⋅n^0.2 and the roughness of the finished surface is directly proportional to d^0.5⋅n^0.2.

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Most of extrusion defects are caused by inhomogeneous flow of materials during extrusion, and there are many singular phenomena resulted from inhomogeneous flow in the outer parts of the products. But few quantitative studies of the metal flow in extrusion, especially near the outer surface of the products with high reductions, have been made. The present work was carried out to study quantitatively the flow of aluminum extruded with high reductions. The redundant strain from center to surface of the products was evaluated and compared with the slip line field theory. The results are summarized as follows:
1) By a unique method of extruding aluminum billets with high purity Au wires as flow line markers, redundant strain values in the outer parts of the extruded bars could be obtained quantitatively.
2) It can be said, within the experimental errors, that the intervals between longitudinal markers of the billet are similarly reduced in the extruded rod. Consequently, the displacement in the direction of the diameter agrees with that in plane strain analysis by the slip line field theory.
3) The flow lines of the products could be represented by a function, Y = a exp (bX), where X is the distance from the center line of the bar, Y is the hight of the marker from X-axis, and a and b are constants. On the other hand, the flow lines from the slip line field theory under equivalent conditions were represented as Y = mXⁿ, where m and n are constants, irrespective of extrusion ratios and friction conditions.
4) The redundant strain in the outer part of the product is almost ten times as much as that from the theory. This may give a clue to make clear the anomalous structure near the surface of the extruded metals.

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