Mo5Si3 single crystals: Physical properties and mechanical behavior

F. Chu, D. J. Thoma, K. J. McClellan, Pedro Peralta

Research output: Contribution to journalArticle

59 Citations (Scopus)

Abstract

The materials processing, physical properties and mechanical behavior of an ultrahigh temperature structural silicide, Mo5Si3, have been studied. High purity single crystals of Mo5Si3 have been synthesized by both optical floating zone and Czochralski methods. The thermal and elastic properties of the Mo5Si3 single crystals were experimentally measured. Results show that Mo5Si3 has significant thermal expansion anisotropy along the a and c directions with αca=2.2. The single crystal elastic moduli of Mo5Si3 indicate that it has less elastic anisotropy and lower shear moduli than transition metal disilicides. Tensile stresses of up to 1.8 GPa can develop at grain boundaries after cooling from the melting point due to the thermal expansion mismatch in Mo5Si3, causing grain boundary cracking during processing of polycrystals. Room temperature Vickers indentation tests on (100) and (001) planes have been performed with different indenter diagonal orientations and the orientation dependence of hardness and fracture toughness of Mo5Si3 single crystals have been obtained. The corresponding deformation and fracture modes have been revealed by microscopy studies. Finally, a comparison of Mo5Si3 with other high temperature structural silicides is discussed.

Original languageEnglish (US)
Pages (from-to)44-52
Number of pages9
JournalMaterials Science and Engineering A
Volume261
Issue number1-2
StatePublished - Mar 15 1999
Externally publishedYes

Fingerprint

Physical properties
physical properties
Single crystals
single crystals
Thermal expansion
thermal expansion
Grain boundaries
Anisotropy
grain boundaries
disilicides
Elastic moduli
Silicides
elastic anisotropy
Crystal growth from melt
Czochralski method
silicides
Polycrystals
polycrystals
toughness
Processing

Keywords

  • Anisotropy
  • Fracture
  • Physical properties
  • Structural silicide

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Mo5Si3 single crystals : Physical properties and mechanical behavior. / Chu, F.; Thoma, D. J.; McClellan, K. J.; Peralta, Pedro.

In: Materials Science and Engineering A, Vol. 261, No. 1-2, 15.03.1999, p. 44-52.

Research output: Contribution to journalArticle

Chu, F. ; Thoma, D. J. ; McClellan, K. J. ; Peralta, Pedro. / Mo5Si3 single crystals : Physical properties and mechanical behavior. In: Materials Science and Engineering A. 1999 ; Vol. 261, No. 1-2. pp. 44-52.
@article{cc906dc99ad04b509b95799f7627a17c,
title = "Mo5Si3 single crystals: Physical properties and mechanical behavior",
abstract = "The materials processing, physical properties and mechanical behavior of an ultrahigh temperature structural silicide, Mo5Si3, have been studied. High purity single crystals of Mo5Si3 have been synthesized by both optical floating zone and Czochralski methods. The thermal and elastic properties of the Mo5Si3 single crystals were experimentally measured. Results show that Mo5Si3 has significant thermal expansion anisotropy along the a and c directions with αc/αa=2.2. The single crystal elastic moduli of Mo5Si3 indicate that it has less elastic anisotropy and lower shear moduli than transition metal disilicides. Tensile stresses of up to 1.8 GPa can develop at grain boundaries after cooling from the melting point due to the thermal expansion mismatch in Mo5Si3, causing grain boundary cracking during processing of polycrystals. Room temperature Vickers indentation tests on (100) and (001) planes have been performed with different indenter diagonal orientations and the orientation dependence of hardness and fracture toughness of Mo5Si3 single crystals have been obtained. The corresponding deformation and fracture modes have been revealed by microscopy studies. Finally, a comparison of Mo5Si3 with other high temperature structural silicides is discussed.",
keywords = "Anisotropy, Fracture, Physical properties, Structural silicide",
author = "F. Chu and Thoma, {D. J.} and McClellan, {K. J.} and Pedro Peralta",
year = "1999",
month = "3",
day = "15",
language = "English (US)",
volume = "261",
pages = "44--52",
journal = "Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing",
issn = "0921-5093",
publisher = "Elsevier BV",
number = "1-2",

}

TY - JOUR

T1 - Mo5Si3 single crystals

T2 - Physical properties and mechanical behavior

AU - Chu, F.

AU - Thoma, D. J.

AU - McClellan, K. J.

AU - Peralta, Pedro

PY - 1999/3/15

Y1 - 1999/3/15

N2 - The materials processing, physical properties and mechanical behavior of an ultrahigh temperature structural silicide, Mo5Si3, have been studied. High purity single crystals of Mo5Si3 have been synthesized by both optical floating zone and Czochralski methods. The thermal and elastic properties of the Mo5Si3 single crystals were experimentally measured. Results show that Mo5Si3 has significant thermal expansion anisotropy along the a and c directions with αc/αa=2.2. The single crystal elastic moduli of Mo5Si3 indicate that it has less elastic anisotropy and lower shear moduli than transition metal disilicides. Tensile stresses of up to 1.8 GPa can develop at grain boundaries after cooling from the melting point due to the thermal expansion mismatch in Mo5Si3, causing grain boundary cracking during processing of polycrystals. Room temperature Vickers indentation tests on (100) and (001) planes have been performed with different indenter diagonal orientations and the orientation dependence of hardness and fracture toughness of Mo5Si3 single crystals have been obtained. The corresponding deformation and fracture modes have been revealed by microscopy studies. Finally, a comparison of Mo5Si3 with other high temperature structural silicides is discussed.

AB - The materials processing, physical properties and mechanical behavior of an ultrahigh temperature structural silicide, Mo5Si3, have been studied. High purity single crystals of Mo5Si3 have been synthesized by both optical floating zone and Czochralski methods. The thermal and elastic properties of the Mo5Si3 single crystals were experimentally measured. Results show that Mo5Si3 has significant thermal expansion anisotropy along the a and c directions with αc/αa=2.2. The single crystal elastic moduli of Mo5Si3 indicate that it has less elastic anisotropy and lower shear moduli than transition metal disilicides. Tensile stresses of up to 1.8 GPa can develop at grain boundaries after cooling from the melting point due to the thermal expansion mismatch in Mo5Si3, causing grain boundary cracking during processing of polycrystals. Room temperature Vickers indentation tests on (100) and (001) planes have been performed with different indenter diagonal orientations and the orientation dependence of hardness and fracture toughness of Mo5Si3 single crystals have been obtained. The corresponding deformation and fracture modes have been revealed by microscopy studies. Finally, a comparison of Mo5Si3 with other high temperature structural silicides is discussed.

KW - Anisotropy

KW - Fracture

KW - Physical properties

KW - Structural silicide

UR - http://www.scopus.com/inward/record.url?scp=0002896532&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0002896532&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0002896532

VL - 261

SP - 44

EP - 52

JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

SN - 0921-5093

IS - 1-2

ER -