Iron Aluminide Composites

PDF Version Also Available for Download.

Description

Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB{sub 2}, and ZrB{sub 2}. In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructure, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed ... continued below

Physical Description

11 p.

Creation Information

Schneibel, J.H. November 20, 1998.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB{sub 2}, and ZrB{sub 2}. In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructure, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength at elevated temperatures (1073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a mile of mixtures. Interestingly, sufficiently thin (< 1 {micro}m) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminizes, environmental embrittlement is dramatically reduced in iron aluminide composites.

Physical Description

11 p.

Notes

OSTI as DE00003928

Medium: P; Size: 11 pages

Source

  • 8th Conference on High-Temperature Ordered Intermetallic Alloys, Boston, MA (US), 11/30/1998--12/04/1998

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: ORNL/CP-101515
  • Report No.: KC 02 01 05 0
  • Grant Number: AC05-96OR22464
  • Office of Scientific & Technical Information Report Number: 3928
  • Archival Resource Key: ark:/67531/metadc685691

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • November 20, 1998

Added to The UNT Digital Library

  • July 25, 2015, 2:20 a.m.

Description Last Updated

  • April 6, 2017, 7:39 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 5

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Schneibel, J.H. Iron Aluminide Composites, article, November 20, 1998; Tennessee. (digital.library.unt.edu/ark:/67531/metadc685691/: accessed September 25, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.