Development of a Mechanically Alloyed Aluminum alloy for 450-650F Service.
Abstract
This investigation was aimed at gaining an understanding of the factors controlling room and elevated temperature strength in aluminum and aluminum alloys prepared by mechanical alloying (M/A). Room temperature strength was found to be controlled by retained cold work, grain size, dispersoid content, precipitation hardening and the presence of low solubility addition elements. Decreasing effectiveness of these factors was found at elevated temperatures and, in fact, the solid solution/precipitation hardening elements decreased strength. Stress-rupture and creep properties were defined as a function of stress, time and alloy additions. The most beneficial addition elements were found to be Ti or a combination of Fe+Cr. Stress to produce 0.2% creep strain in 100 hours was estimated to be 22.6 ksi at 450 F and 13.9 ksi at 650 F. Attempts to improve creep resistance by increasing grain size through variations in hot working were unsuccessful. Creep strength at 450 F was less in the grain coarsened materials than in those with fine grains, and at 650 F was independent of grain size over the limited range evaluated. Continued attempts at affecting recrystallization to a coarse elongated grain morphology, as achieved in nickel base systems, should be made. Such a structure is expected to increase creep strength at service temperatures greater than 50% of the absolute melting point, 380 F in the case of Al.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA090597
Entities
People
- Donald L. Erich
Organizations
- University of Cincinnati