The precipitation behavior and strengthening of a Cu-2.0 wt% Be alloy

The phase transformation and precipitation process of a 07200 Cu-2.0 wt% Be alloy during the aging process at 320 degrees C are investigated in this study. It is confirmed that the phase transformation of the alloy follows the sequence of GP zones -> gamma '' -> gamma' -> gamma phase. The electrical conductivity is found to increase by the precipitation of solute elements from copper matrix. The change of electric conductivity can be used to describe the dynamic process of precipitation by an equation based on the Avrami law. The strength of the alloy increases tremendously to more than 1000 MPa only after a short time at 320 degrees C. Peak strength can be obtained at an aging time of 4 h with microstructures containing mainly gamma '' and gamma' phases, and then the strength decreases with further aging. The strength of the specimen aged for 16 h is still much higher than that of solution state, suggesting that the main strengthening of the by-cutting mechanism has not changed for the C17200 Cu-Be alloy. (C) 2012 Elsevier B.V. All rights reserved.