Accession Number:

AD0761215

Title:

Modification and Control of Oxide Structures on Metals and Alloys: (Phase III)

Descriptive Note:

Final rept. 20 Dec 1971-20 Jan 1973

Corporate Author:

WESTINGHOUSE ASTRONUCLEAR LAB PITTSBURGH PA

Personal Author(s):

Report Date:

1973-02-01

Pagination or Media Count:

199.0

Abstract:

The rutile structure family for oxide compounds of the type NbBO4 where B Cr, Al, or Fe have been identified as being the primary oxide phase in the scales formed on oxidation resistant Nb intermetallic compounds and Nb-Ti- Cr-Al, Nb-Fe-Al, Nb-Cr-Al-Co, and Nb-Cr-Al-Ni alloys. Along with this oxide, small amounts of either B2O3 where B Cr, Al, or Fe or a CoAl2O4 spinel in cobalt containing alloys were detected. Oxygen transport rates through Nb2O3- Cr2O3, Nb2O5-TiO2, Nb2O5-ZrO2, and Nb2O5-Al2O3 were also determined using thermogravimetric techniques. Of the oxide compounds evaluated, only oxygen transport through Nb2O5-Cr2O3 was slow enough to warrent its classification as a protective scale. In addition to oxidation rate data, metallographic studies and electron microprobe studies are reported for the Nb intermetallic compounds and alloys.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE