Accession Number:

ADA282404

Title:

Micromechanics of Interfaces in Metal Matrix Composites

Descriptive Note:

Final technical rept.

Corporate Author:

MINNESOTA UNIV MINNEAPOLIS

Report Date:

1994-07-12

Pagination or Media Count:

69.0

Abstract:

The mechanical properties of the interfaces in an Al2O3 fiber reinforced beta-2lS titanium have been evaluated by using fiber pushout tests. The Al2O3 fibers were coated with a refractory metal and Y2O3 which served as a diffusion barrier during the HIPing used to produce the metal matrix composites. By doing fiber pushout tests the interfacial fracture was found to occur at the interface between the refractory metal and the H2O3. The interfacial shear strength and interfacial frictional stress were measured to be 323 and 312 or - 2 MPa, respectively. The interfacial frictional stress, which is due to asperity interlocking during the fiber sliding, was correlated to the surface roughness of the coated Al2O3 fiber obtained with the aid of an atomic force microscope. The measured surface roughness of 18.8 or - 2.2 nm was related to the frictional stress through Hutchinsons model. The frictional coefficient between the Al2O3 fiber and the Ti matrix calculated to be 0.32 or - 0.02

Subject Categories:

  • Laminates and Composite Materials
  • Properties of Metals and Alloys
  • Fabrication Metallurgy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE