0
Gas Turbines: Ceramics

Tension-Compression Fatigue of a SiC/SiC Ceramic Matrix Composite at Elevated Temperature

[+] Author and Article Information
M. B. Ruggles-Wrenn, T. P. Jones

Department of Aeronautics and Astronautics,  Air Force Institute of Technology, Wright-Patterson Air Force Base, OH 45433-7765

J. Eng. Gas Turbines Power 134(9), 091301 (Jul 23, 2012) (6 pages) doi:10.1115/1.4006989 History: Received June 18, 2012; Revised June 18, 2012; Published July 23, 2012; Online July 23, 2012

Tension-compression fatigue behavior of a nonoxide ceramic composite with a multilayered matrix was investigated at 1200 °C in laboratory air. The composite was produced via chemical vapor infiltration (CVI). The composite had an oxidation inhibited matrix, which consisted of alternating layers of silicon carbide and boron carbide and was reinforced with laminated Hi-Nicalon™ fibers woven in an eight-harness-satin weave (8HSW). Fiber preforms had pyrolytic carbon fiber coating with boron carbon overlay applied. Tension-compression fatigue behavior was studied for fatigue stresses ranging from 80 to 200 MPa at a frequency of 1.0 Hz. The R ratio (minimum stress to maximum stress) was −1.0. Fatigue run-out was defined as 2 × 105 cycles. Fatigue limit was 80 MPa. Specimens that achieved fatigue run-out were subjected to tensile tests to failure to characterize the retained tensile properties. The material retained 100% of its tensile strength. Reductions in tensile modulus and in compressive modulus were negligible. Composite microstructure, as well as damage and failure mechanisms were investigated.

FIGURES IN THIS ARTICLE
<>
Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

(a) Typical microstructure. (b) Oxidation inhibited matrix consisting of alternating layers of SiC and B4 C. (c) Fibers and PyC fiber coating with B4 C overlay.

Grahic Jump Location
Figure 2

Test specimen. All dimensions in inches.

Grahic Jump Location
Figure 3

Fatigue S-N curves for Hi-N/SiC-B4 C at 1200 °C in air. Tension-tension fatigue data from Ruggles-Wrenn [25].

Grahic Jump Location
Figure 4

Typical evolution of stress-strain hysteresis response of Hi-N/SiC-B4 C composite with fatigue cycles at 1200 °C in air: (a) σmax  = 80 MPa, (b) σmax  = 200 MPa

Grahic Jump Location
Figure 5

Maximum and minimum strains versus fatigue cycles for Hi-N/SiC-B4 C ceramic composite at 1200 °C in air

Grahic Jump Location
Figure 6

Normalized modulus versus fatigue cycles for Hi-N/SiC-B4 C ceramic composite at 1200 °C in air

Grahic Jump Location
Figure 7

Fracture surface of the specimen tested at 1200 °C (a) in tension-compression fatigue and (b) in tension-tension fatigue. Tension-tension fracture surface from Ruggles-Wrenn [25].

Grahic Jump Location
Figure 8

Fracture surface of the specimen tested in tension-compression fatigue with σmax  = 160 MPa. SEM micrographs showing: (a) oxidation of fibers and matrix and (b) glassy phase in the oxidized region, (c) fiber pull-out and (d) no degradation of fiber-matrix interphase typical in the not oxidized region.

Grahic Jump Location
Figure 9

Schematic showing matrix cracks developing in tension, compression, and tension-compression loading

Grahic Jump Location
Figure 10

SEM micrograph showing matrix cracks oriented transverse to and parallel to the loading direction

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In