Foreign Object Damage by Steel Ball Projectiles in a SiC/SiC Ceramic Matrix Composite at Ambient and Elevated Temperatures
Abstract
Foreign object damage (FOD) phenomenon of a gas-turbine grade SiC/SiC ceramic matrix composite was determined at 25 deg C and 1316 deg C using impact velocities ranging from 115 to 440 m/sec by 1.59-mm diameter steel ball projectiles. Two types of target-specimen support were employed at each temperature: fully supported and partially supported. For a given temperature, the degree of post-impact strength degradation increased with increasing impact velocity, and was greater in a partially supported configuration than in a fully supported one. The elevated-temperature FOD resistance of the composite, particularly in partial support at higher impact velocities >=350 m/sec, was significantly less than the ambient-temperature counterpart, attributed to a weakening effect of the composite. In full support, frontal contact stress played a major role in generating composite damage; whereas, in partial support, both frontal contact and backside flexure stresses were combined sources of damage generation. Formation of cone cracks initiating from impact site was also one of the key damage aspects. The SiC/SiC composite was able to survive higher energy impacts without complete structural failure, as compared to gas-turbine grade AS800 and SN282 monolithic silicon nitrides.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 29, 2008
- Accession Number
- ADA481739
Entities
People
- Donald J. Alexander
- Sung R. Choi
Organizations
- Naval Air Warfare Center