Effect of microstructure on internal friction and Young's modulus of aged Cu-Be alloy

This study is intended to determine the effect of microstructure on internal friction and Young's modulus as a function of stress in the elastic region of an aged Cu-Be alloy and to investigate the influence of transformed phases caused by precipitation hardening on both properties. Results show that internal friction and Young's modulus were influenced by different precipitates. Transformed phases and micromechanical mechanisms could be responsible for the changes in internal friction and Young's modulus. The microstructure of the alloy having Guinier-Preston zones appears to have low internal friction and dependence on stress after aging at 315 degrees C for 2 h. The Young's moduli of the long-term aged samples increased by approximately 2 GPa compared to that for the short-term aged samples and elastic instability up to a stress of 20% of the yield strength was observed. (C) 2009 Elsevier B.V. All rights reserved.