Doctoral Dissertations

Abstract

"Cr3Si has many desirable properties for use as a high temperature structural material: a high melting point, high stiffness and good chemical resistance. However, like many intermetallics, it suffers from a low toughness at room temperature. To overcome this limitation, ductile second phase toughening has been examined using chromium as the second phase.

Specimens of Cr-Cr3Si composites were produced by powder metallurgy techniques. The mechanical properties of these composites were evaluated using microhardness indentation to calculate a toughness value and in some cases notched three- point bend bars were also used. Examination of the Cr phase of these composites indicated that it lacked sufficient toughness itself to produce the desired toughness in the composite. Mechanical alloying was then used to create chromium alloys that were hot pressed and tested using the three-point bend method. The addition of 0.5 at. % V to Cr with 7.0 at.% Si (representative of the chromium phase of the composite) showed the largest increase in toughness, a 60% increase. Chromium with 0.5 at. % V was then used to make a composite with Cr3Si.

Mechanical alloying was also used to produce a (Cr,Mo)3Si material, which should have superior high temperature properties compared to Cr3Si. This material was then used to produce composites with Cr and Cr-0.5 V. The composites had twice the toughness compared with similar composites produced with Cr3Si"--Abstract, page iv.

Advisor(s)

Newkirk, Joseph William

Committee Member(s)

Askeland, Donald R.
Van Aken, David C.
Kohser, Ronald A.
Ownby, P. D.

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Metallurgical Engineering

Publisher

University of Missouri--Rolla

Publication Date

Spring 1998

Pagination

xi, 136 pages

Note about bibliography

Includes bibliographical references (pages 128-135).

Rights

© 1998 Terry Alan Cruse, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Thesis Number

T 7456

Print OCLC #

40166963

Electronic OCLC #

1079065470

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

http://laurel.lso.missouri.edu/record=b4096317~S5

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