タンデム式縦型高速双ロールキャスト法で作製した4045/3003/4045アルミニウム合金クラッド材の組織と機械的性質

抄録

4045/3003/4045 aluminum alloy clad sheets having the same thickness (6.0 mm) and clad ratio (12%) were fabricated both by hot roll-bonding and vertical-type high-speed tandem twin-roll casting. The clad sheets were cold-rolled to 0.17 mm in thickness, annealed at 400°C for 2 h, cold-rolled to 0.10 mm in thickness and finally subjected to heat treatment for brazing at 600°C for 3 min. Microstructures and mechanical properties of the clad sheets were investigated in each stage. Al–Mn dispersoid particles in the core (A3003) and Si particles in the overlay (A4045) of the cold-rolled sheet with 0.17 mm thickness originating from the twin-roll casting were smaller than those originating from the hot roll-bonding. Interfaces between the core and the overlay were clearly observed in the twin-roll casting sheets. A fully recrystallized structure was observed after annealing in the sheet originating from the hot roll-bonding, while the fibrous structure still remained in the sheet originating from the twin-roll casting. Yield strength, tensile strength and elongation of the annealed sheet originating from the twin-roll casting were higher than those originating from the hot roll-bonding. After heat treatment for brazing, the tensile strength was the same in both clad sheets.