New Metallophilic Colloidal Ceramics
Abstract
In this study, TRA has examined the possibility of using alumina and/ or thoria for dispersion hardening of aluminum base alloys. Thoria apparently is not wetted by the aluminum alloy, and hence does not appear to be a candidate for the intended use. On the other hand, alumina is wetted and has been dispersed in a submicron state. The opportunity to produce aluminum alloys with superior high temperature strength is real. The conditions for wetting submicron alumina into a molten alloy of aluminum-copper-magnesium have been demonstrated. This was accomplished by adding copper-alumina master mix slugs to molten aluminum-magnesium. The alloy containing the dispersed oxide was cast and the resulting metal analysed by electron microscopy and hardness after working followed by annealing. Hardness showed retention of properties of annealing. The micrographs showed alumina dispersed uniformly throughout the cast structure at an interparticle (IPS) spacing in the range of 150-200 millimicrons. This is even smaller than the spacing of particles in TD Nickel. Control of IPS at any level from 100 millimicrons and up has been demonstrated. The new alloy, called oxide dispersion strengthened aluminum or ODS aluminum, is expected to have useful metallurgical strength, at 500-550 C, and thus increase the useful temperature range of aluminum base alloys by at least 200 centigrade degrees.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 12, 1984
- Accession Number
- ADA214714
Entities
People
- Guy B. Alexander
- J. K. Weeks Jr.