METALLOGRAPHY OF S.A.P. ALLOYS AND ITS RELATION TO CREEP RESISTANCE.
Abstract
The structures of several different S.A.P. alloys (sintered aluminium-alumina powder metallurgy alloys) have been investigated by means of transmission electron metallography. The dispersed aluminium oxide has been shown to be alpha-Al2O3. The aluminium matrix of all the samples examined will not undergo grain growth until the metal has been deformed greater than 98% reduction in thickness. It is suggested that the orientation of the oxide plates may effect the grain growth. Specimens have been examined after creep tests and stress rupture tests but no significant structural changes can be observed. It is suggested that the creep strength is due to the complete stability of the dispersed oxide phase up to the melting point of the matrix and also to the small stable grain size of the matrix. Heat treatments carried out above the melting point of the matrix have shown that a massive honeycomb network of oxide is produced which may explain the creep results of others workers obtained above the melting point of the aluminium. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1964
- Accession Number
- AD0608868
Entities
People
- D. W. Dawe
- I. S. Brammer