Download or read book Aging Study of 2024 Aluminum by Dynamic Modulus Techniques written by G. W. King and published by . This book was released on 1962 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic modulus measurements are used to study precipitation rates in 2024 Al alloy. The results are discussed in terms of the effect of structural changes on the elastic modulus as well as the kinetics of precipitation at various stages of the age-hardening process. Activation energies were determined for aging in the temperature ranges from room (77 F) to 130 F, and 375 F to 425 F. A value of 20.7 kcal/gm mole was obtained for the lower temperature range, and 23 kcal/gm mole for the higher temperatures. The data indicate that modulus changes are primarily influenced by the structure of the second phase, however, some evidence of strain energy effects are indicated. (Author)