Accession Number:

ADA273835

Title:

Investigation of Compressive Behavior for Metal Matrix Composites with a Circular Hole

Descriptive Note:

Master's thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1993-12-01

Pagination or Media Count:

135.0

Abstract:

This study investigated the notched and unnotched macromechanical response due to micromechanical behavior of O-4590 sub s SCS-6beta 21 S and 0902 sub S SigmaBeta 21S subjected to static compressive loads at room temperature. The stress-strain behavior and mechanical response in the presence of a circular hole was examined. A clear description of the progressive nature of damage, which ultimately resulted in failure, was provided. The effect of elevated temperature was shown for SCS-6Beta 21S. The ultimate compressive strength and elastic modulus were reported for both MMCs. SigmaBeta 21S and SCS-6Beta 21S were mildly notch sensitive at room temperature. Notch sensitivity of SCS-6Beta 21S was slightly reduced at 650 deg C. Internal failure mechanisms of fiber debonding, matrix cracking, matrix yielding, fiber failure, and fiber microbuckling were observed in various combinations during the loading. Damage mechanisms were observed similarly in notched and unnotched specimens. Damage initiation in the notched specimens was concentrated in the region adjacent to the hole. SigmaBeta 21S and unnotched SCS-6Beta 21S at room temperature failed in an extensional mode, while notched SCS-6Beta 21S and unnotched SCS-6Beta 21S at 650 deg C failed in a shear mode. The ultimate compressive failure of each depended on the ultimate strength of the fibers.

Subject Categories:

  • Laminates and Composite Materials
  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE