Abstract
Fatigue tests were conducted at 1273K using smooth bar specimens of a nickel-based single crystal superalloy CMSX-10, and small cracks were observed on the surface of the specimens by means of microscope. It was clarified by the observation that fatigue fracture of CMSX-10 takes place as follows; (1) Oxide-layer was formed on the surface of the specimen. (2) A lot of small cracks of the size of about 100μm were initiated perpendicular to the stress axis on the surface of the oxide-layer. (3) Some of them grew and penetrated the oxide-layer to reach the base metal. Processes (1) to (3) were completed at the very early stage of fatigue life. (4) Growth of the cracks that reached the base metal brought about the final fracture. As the formation of oxide-layer on the surface of the specimen was considered to be a trigger of crack initiation, a fatigue test was also conducted with repeated removal of the oxide-layer by emery paper and diamond paste. In this test, no crack appeared on the surface of the specimen even at 20000 cycles when a lot of cracks were observed in the normal fatigue tests. This proves that removal of the oxide-layer retards the initiation of small cracks and extends the fatigue life.
| Original language | English |
|---|---|
| Pages (from-to) | 129-136 |
| Number of pages | 8 |
| Journal | Zairyo/Journal of the Society of Materials Science, Japan |
| Volume | 50 |
| Issue number | 2 |
| Publication status | Published - Feb 2001 |
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Keywords
- CMSX-10
- High-temperature fatigue
- Nickel-based superalloy
- Oxide-layer
- Single crystal
- Small cracks
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Metals and Alloys
- Polymers and Plastics
Cite this
Fracture process in high-temperature fatigue of Ni-based single crystal superalloy CMSX-10 and effect of removal of surface oxide-layer on crack initiation. / Tada, Naoya; Ohtani, R.; Shibata, M.; Kobayashi, T.
In: Zairyo/Journal of the Society of Materials Science, Japan, Vol. 50, No. 2, 02.2001, p. 129-136.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fracture process in high-temperature fatigue of Ni-based single crystal superalloy CMSX-10 and effect of removal of surface oxide-layer on crack initiation
AU - Tada, Naoya
AU - Ohtani, R.
AU - Shibata, M.
AU - Kobayashi, T.
PY - 2001/2
Y1 - 2001/2
N2 - Fatigue tests were conducted at 1273K using smooth bar specimens of a nickel-based single crystal superalloy CMSX-10, and small cracks were observed on the surface of the specimens by means of microscope. It was clarified by the observation that fatigue fracture of CMSX-10 takes place as follows; (1) Oxide-layer was formed on the surface of the specimen. (2) A lot of small cracks of the size of about 100μm were initiated perpendicular to the stress axis on the surface of the oxide-layer. (3) Some of them grew and penetrated the oxide-layer to reach the base metal. Processes (1) to (3) were completed at the very early stage of fatigue life. (4) Growth of the cracks that reached the base metal brought about the final fracture. As the formation of oxide-layer on the surface of the specimen was considered to be a trigger of crack initiation, a fatigue test was also conducted with repeated removal of the oxide-layer by emery paper and diamond paste. In this test, no crack appeared on the surface of the specimen even at 20000 cycles when a lot of cracks were observed in the normal fatigue tests. This proves that removal of the oxide-layer retards the initiation of small cracks and extends the fatigue life.
AB - Fatigue tests were conducted at 1273K using smooth bar specimens of a nickel-based single crystal superalloy CMSX-10, and small cracks were observed on the surface of the specimens by means of microscope. It was clarified by the observation that fatigue fracture of CMSX-10 takes place as follows; (1) Oxide-layer was formed on the surface of the specimen. (2) A lot of small cracks of the size of about 100μm were initiated perpendicular to the stress axis on the surface of the oxide-layer. (3) Some of them grew and penetrated the oxide-layer to reach the base metal. Processes (1) to (3) were completed at the very early stage of fatigue life. (4) Growth of the cracks that reached the base metal brought about the final fracture. As the formation of oxide-layer on the surface of the specimen was considered to be a trigger of crack initiation, a fatigue test was also conducted with repeated removal of the oxide-layer by emery paper and diamond paste. In this test, no crack appeared on the surface of the specimen even at 20000 cycles when a lot of cracks were observed in the normal fatigue tests. This proves that removal of the oxide-layer retards the initiation of small cracks and extends the fatigue life.
KW - CMSX-10
KW - High-temperature fatigue
KW - Nickel-based superalloy
KW - Oxide-layer
KW - Single crystal
KW - Small cracks
UR - http://www.scopus.com/inward/record.url?scp=0035246594&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035246594&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0035246594
VL - 50
SP - 129
EP - 136
JO - Zairyo/Journal of the Society of Materials Science, Japan
JF - Zairyo/Journal of the Society of Materials Science, Japan
SN - 0514-5163
IS - 2
ER -