Consolidation of N₂ gas atomized powders of Al-9 mass%Fe alloy was done by cold pressing, degassing, hot pressing and extrusion at a reduction ratio of 7 to 1. The degassing was carried out at various temperatures between room temperature and 500°C, while both hot pressing and extrusion were carried out at a fixed temperature of 300°C at which no coarsening of intermetallic compounds occurs at all. The dehydration of surface oxide film on the powder particles is accelerated with increase in the degassing temperature, making the oxide layer more brittle. When the degassing is carried out below 300°C, the room temperature strength of the extruded rod is high, but the toughness remains low showing rapid decrease with slight increase of strength (or with decrease of degassing temperature). On the contrary, the strength decreases and the toughness increases with increasing degassing time and temperature above 400°C, and this is attributed to the coarsening of Al-Fe compounds during degassing. One reason why low temperature degassing brings about a low toughness is that the strength of extruded rod is kept at high level, and another can be that cracks propagate preferentially along the prior powder particle boundaries where exist continuous oxide layers which were broken-up neither by degassing nor by extrusion.

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Effect of heat treating condition and chemical composition on mechanical properties and microstructures were studied on squeeze cast AC4CH alloy. Both squeeze cast AC4CH alloys modified and not modified have high elongation and tensile strength because of rapid spherodization of fine eutectic Si crystal during solution heat treatment, small dendrite arm spacing and high density. Influence of Fe content on reduction of elongation is very small between 0.1%Fe and 0.3%Fe. Because Al-Si-Mg-Fe compounds are spherodized during solution treatment.

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Compound βMg₂Al₃ is apt to be formed in squeeze cast Al-5%Mg alloy. As a result there is lowering in elongation and ultimate strength. Since addition of Si leads to fine eutectic Mg₂Si in Al-5%Mg-Si alloy, the ultimate strength increases with a little lowering of elongation. But the mechanical properties falls with increase in thickness of sample. Addition of Zn does not lead to increase of ultimate strength because of formation of Al-Mg-Zn compounds.

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Bonding interfaces of friction- and explosive-welded aluminum-titanium joints, before and after annealing for 1h at temperatures between 723 and 923K, were examined by tensile test for bonding strength, and by optical and electron micrographies, and EPMA for phases in interfacial reaction-layers. Results obtained are as follows:
(1) Bonding strength of both friction- and explosive-welded joints in the as-welded and annealed states is higher than the tensile strength of aluminum matrix in each specimen. Thus, fracture occurs in the aluminum matrix.
(2) The interfacial reaction layer consists of only Al₃Ti in the case of friction-welded joint, and Al₃Ti and AlTi in the explosive-welded joint.
(3) These phases are so stable that the thickness of the layer is kept almost the same by the annealing.

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Ribbon-shaped Al-Mn-Zr alloys obtained by rapid solidification were consolidated into full density billets by vacuum hot-press (1st step) and hot-extrusion processes (2nd step). The structural changes of the alloys through these processes were assessed. The 1st step consolidation process causes to decompose the supersaturated solid solution (SSS) and to precipitate a needle or plate-like particles lying parallel with <110>_matrix. The 2nd step process gives rise to decompose the SSS to a practically equilibrium state. The decomposition structures are constructed from Al₆Mn precipitates of a sub-micron size showing statistically the log-normal distribution. The extruded alloys shows an acceptable ductility and also a linear relationship between the tensile strength and manganese content is indicated.

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