Masters Theses
Abstract
"In a previous study on Cr-Cr3Si in-situ composites, samples were arc melted1. A yield strength of 359 MPa at 1200°C was reported for an alloy of 25% Cr and 75% Cr3Si. This strength, as well as the low temperature strength and toughness need to be enhanced for use in high temperature gas turbine engine applications. In this study, two approaches were taken to improve the strength and toughness of the Cr-Cr3Si in-situ composite at low and elevated temperatures. These two approaches were powder metallurgy and dispersion strengthening. Powder metallurgy was used to produce a more equiaxed microstructure than was observed in the arc melted alloys in an attempt to improve both strength and toughness. The other approach, dispersion strengthening, used erbia as a dispersoid to improve the elevated temperature strength.
Samples of Cr-15.5Si with erbia were produced by arc melting. High density samples of Cr-15.5Si and Cr-18.6Si were produced by hot pressing chromium and chromium silicide powders in a graphite die. These samples were made with and without erbia for comparison purposes.
Four-point bend and Vickers microhardness testing were performed to evaluate the mechanical properties of the alloys. The microhardness indentations were also used to evaluate the toughness. Optical and electron microscopy was used to characterize the microstructures. The properties of the alloys were affected by hot pressing and the erbia. The erbia also aided in the consolidation of the hot-pressed samples. A Cr-15.5Si alloy with erbia was produced with a density 98% of theoretical"-Abstract p. iii
Advisor(s)
Joseph W. Newkirk
Committee Member(s)
Donald R. Askeland
Lokeswarappa R. Dharani
Department(s)
Materials Science and Engineering
Degree Name
M.S. in Metallurgical Engineering
Publisher
University of Missouri--Rolla
Publication Date
Spring 1995
Pagination
ix, 67 pages
Note about bibliography
Includes bibliographical references (pages 64-66)
Rights
© 1995 Joseph Edward Price, All rights reserved.
Document Type
Thesis - Restricted Access
File Type
text
Language
English
Thesis Number
T 6961
Print OCLC #
32844777
Recommended Citation
Price, Joseph E., "Processing of dispersion strengthened chromium-silicon alloys" (1995). Masters Theses. 1427.
https://scholarsmine.mst.edu/masters_theses/1427
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