Al-Cu合金単結晶における機械的性質の変形温度依存性

抄録

Al-0.5, 1.0 and 1.5 at% Cu alloy single crystals were quenched from 500°C. All the alloys allow a similar stress-strain behavior. The stress-strain curves show serrations near room temperature and yielding phenomena above 300°C. CRSS reversely depends on temperatures from -78° to 80°C. A peculiar maximum in CRSS is found at 80°C. When the strain rate in this region changes from ε₁ to ε₂ (ε₁ > ε₂), difference in the flow stress decreases resulting inτ₂ > τ₁ at room temperature. Edge dislocations forming dipoles uniformly distribute at -196°C, and tend to cluster at elevated temperatures. Long dislocation loops are found at 100°C, which are formed by the intersection with prismatic dislocation loops grown during heating. A peak in CRSS at 80°C and a stress exponent above 300°C are also theoretically described.