THE EFFECT OF DISPERSIONS ON THE CREEP PROPERTIES OF ALUMINUM-COPPER ALLOYS
Abstract
The creep properties of Al-Cu alloys containing dispersions of CuAl sub 2 in the alpha solid-solution matrix of Al were primarily dependent on the volumetric mean free path () between the CuAl sub 2 particles and independent of minor variations in composition (3 to 5% Cu) and heat treatment. The creep stress correlated with the creep rate-temperature parameter Z = epsilon sub s sub e delta H/RT, where sub s is the secondary creep rate, delta H the activation energy, R the gas constant, and T the absolute temperature during creep. Above ln Z = 46 and below ln Z = 27.5, the finer dispersions exhibited superior creep resistance; in the intervening range, the coarser dispersions were superior. CuAl sub 2 dispersions increased the Al creep resistance above that obtained by alloying with Cu. delta H was a constant of about 37,000 cal/ mol. Constant-load creep strains for dispersion alloys appeared to be functions of the initial stress and the temperature-compensated time, analogous to the creep behavior of alpha solid solutions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1952
- Accession Number
- AD0000691
Entities
People
- John E. Dorn
- Oleg D. Sherby
- Warren H. Giedt
Organizations
- University of California, Berkeley