Increase in critical stress for crack-healing of Si3N4/SiC ceramics by shot peening

Title

Increase in critical stress for crack-healing of Si3N4/SiC ceramics by shot peening

 Author

Takahashi, K.
Nakagawa, S.
Osada, T.

Date

2013-06-16

 Abstract

The effects of shot peening on the critical stress for crack-healing of Si3N4/SiC composite ceramics were investigated. Shot peening was carried out on a Si3N4/SiC composite with a surface crack by using yttrium-stabilized zirconia beads. Shotpeened specimens were crack-healed at 1100 °C for 5 h under a tensile stress (?app) in the range 0–500 MPa. The results clearly showed that the surface cracks in shotpeened specimens were healed completely for ?app ? 450 MPa. Thus, the critical stress for crack-healing (?C app) was determined to be 450 MPa. This ?C app value was 2.3 times that for an unpeened specimen. Furthermore, the ?C app values for both specimens showed a proportional relationship with the bending strength of the cracked specimen ?c (?C app ? 0.64?c). Therefore, it can be concluded that the increase in ?C app of the peened specimen is due to the compressive residual stress and the consequently increase in ?c.

 Subject

ceramics
crack-healing
shot peening
residual stress
critical stress

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http://resolver.tudelft.nl/uuid:5f207a16-237c-448b-bf33-464e220449ad

 Part of collection

Conference proceedings

 Document type

conference paper

 Rights

(c) 2013 Takahashi, K.; Nakagawa, S.; Osada, T.
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