No abstract

The effect of Ag concentrations of up to 0.9 mass% on the precipitation of the strengthening phases in Al-4.6Cu-0.3Mg casting alloy were investigated. Microstructural features were elucidated by optical microscopy, electron probe X-ray microanalysis, measurement of electrical conductivity and differential scanning calorimetry. The microstructure was correlated with Rockwell hardness. The results revealed that the addition of Ag at a concentration of under 0.6 mass% promoted the precipitation of the and 0 phases and the augmentation of hardness of T7 tempered alloys. 0.9 mass% Ag caused the extensive precipitation of the phase, but only mildly suppressed the precipitation of the 0 phase, slightly increasing the hardness. The high density of the precipitates of the phase is responsible for the excellent thermal stability and mechanical properties of the microstructure. The precipitates out before the 0 phase, and does so more quickly, during the aging process.

No abstract

No abstract

No abstract