Project Title:

Novel Higher Temperature Aluminum Alloys by Rapid Consolidation of Glassy

04.07-1933
901318
Novel Higher Temperature Aluminum Alloys by Rapid Consolidation of Glassy

Abstract:

NASA has interest in new aluminum alloys of non-equilibrium chemistries with the
objective of increasing the upper use temperature by 200F. Prior art has dealt with
the use of rapid solidification to form fine grained crystalline alloys based on
Al-Fe-V-Si, Al-Fe-Ce, and Al-Fe-Mo-V. While these alloys have shown promise in improving
use temperature, significant further improvement could be feasible by controlled
crystallization and consolidation of recently developed high crystallization temperature
glassy alloys (Tc=450C). However, conventional consolidation processes such as hot
pressing and hot isostatic processing are not amenable to simultaneous requirements
of full density, small grain size low cost. Recently, a quasi-isostatic high pressure
consolidation process developed by the firm enables consolidation at short times
(5-30 secs.) and at lower temperatures than hot isostatic processing while achieving
full density. Phase I will evaluate the feasibility of producing fully dense, ultrafine
grained aluminum alloys by controlled crystallization of a glassy aluminum Al-Si-Fe-Y
alloy which if thermally stable to high temperatures.
Phase I is expected to show that the goal of attaining 200F increases in use temperature
of aluminum alloy is feasible. The data generated in Phase I will enable Phase II
to focus on upscaled fabrication of large billets and will involve evaluation of
metal working to form sheets, forgings, and plates. Extensive mechanical testing
will also be carried out in Phase II.
metallic glass, crystallization, high temperature, alloy, rapid solidification