Undercooling of Aluminum Alloys
Abstract
The development of refined microstructures for dispersion strengthening of Aluminum alloys by rapid solidification is related to the undercooling at nucleation and during competitive crystal growth. With controlled droplet samples the important processing parameters that govern undercooling in the powders have been identified and include powder size and coating melt cooling rate and superheat. The droplet method has yielded measured undercoolings of 175 C for AL and values near 300 C for some AL alloys. Droplet studies have been valuable in examining the solidification pathways including thermal history effects associated with rapid solidification and dispersoid formation in Aluminum-Nickel, Aluminum-Iron, and Aluminum-Beryllium alloys. Based on the analysis of solidification pathways, microstructure maps may be developed to identify the processing that can yield fine-scale eutectics, metastable structures or suppression of coarse primary intermetallic phases which are useful for the development of dispersoid structures. (jg)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1988
- Accession Number
- ADA217798
Entities
People
- D. U. Furrer
- John H. Perepezko
Organizations
- University of Wisconsin–Madison