Abstract
The geometric features of clustered shrinkage pores (CSP) in ill-conditioned aluminum alloy die castings were revealed and their effect on the fatigue strength was discussed. To obtain the geometric features of CSP, an observation using a commercial microfocus X-ray computed tomography (X-ray CT) system was carried out and the position and size of CSP were confirmed. However, the detailed geometry of the CSP could not be clearly observed by X-ray CT, because each pore in the CSP was too small to observe owing to the insufficient resolution of the CT image. We developed a serial sectioning system with a polishing machine and an optical microscope. Observation using the serial sectioning system clearly showed that a CSP consists of many interconnected small pores, which formed an extremely complicated shape. The CSP was thought to grow from relatively large gas pores, which connect to small pores and consequently generate a cavity with a huge volume and a complicated geometry. The complex geometry of CSP resulted in the concentration of stress around CSP, and significantly undermines mechanical properties such as tensile strength and fatigue strength.
| Original language | English |
|---|---|
| Pages (from-to) | 1574-1580 |
| Number of pages | 7 |
| Journal | Materials Transactions |
| Volume | 51 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 2010 Sep |
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Keywords
- Aluminum alloy
- Casting defect
- Die casting
- Fatigue
- Serial sectioning
- Shrinkage porosity
- X-ray computed tomography
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering
- Mechanics of Materials
Cite this
Clustered shrinkage pores in ill-conditioned aluminum alloy die castings. / Hangai, Yoshihiko; Kuwazuru, Osamu; Yano, Takayuki; Utsunomiya, Takao; Murata, Yozo; Kitahara, Soichiro; Bidhar, Sujit; Yoshikawa, Nobuhiro.
In: Materials Transactions, Vol. 51, No. 9, 09.2010, p. 1574-1580.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Clustered shrinkage pores in ill-conditioned aluminum alloy die castings
AU - Hangai, Yoshihiko
AU - Kuwazuru, Osamu
AU - Yano, Takayuki
AU - Utsunomiya, Takao
AU - Murata, Yozo
AU - Kitahara, Soichiro
AU - Bidhar, Sujit
AU - Yoshikawa, Nobuhiro
PY - 2010/9
Y1 - 2010/9
N2 - The geometric features of clustered shrinkage pores (CSP) in ill-conditioned aluminum alloy die castings were revealed and their effect on the fatigue strength was discussed. To obtain the geometric features of CSP, an observation using a commercial microfocus X-ray computed tomography (X-ray CT) system was carried out and the position and size of CSP were confirmed. However, the detailed geometry of the CSP could not be clearly observed by X-ray CT, because each pore in the CSP was too small to observe owing to the insufficient resolution of the CT image. We developed a serial sectioning system with a polishing machine and an optical microscope. Observation using the serial sectioning system clearly showed that a CSP consists of many interconnected small pores, which formed an extremely complicated shape. The CSP was thought to grow from relatively large gas pores, which connect to small pores and consequently generate a cavity with a huge volume and a complicated geometry. The complex geometry of CSP resulted in the concentration of stress around CSP, and significantly undermines mechanical properties such as tensile strength and fatigue strength.
AB - The geometric features of clustered shrinkage pores (CSP) in ill-conditioned aluminum alloy die castings were revealed and their effect on the fatigue strength was discussed. To obtain the geometric features of CSP, an observation using a commercial microfocus X-ray computed tomography (X-ray CT) system was carried out and the position and size of CSP were confirmed. However, the detailed geometry of the CSP could not be clearly observed by X-ray CT, because each pore in the CSP was too small to observe owing to the insufficient resolution of the CT image. We developed a serial sectioning system with a polishing machine and an optical microscope. Observation using the serial sectioning system clearly showed that a CSP consists of many interconnected small pores, which formed an extremely complicated shape. The CSP was thought to grow from relatively large gas pores, which connect to small pores and consequently generate a cavity with a huge volume and a complicated geometry. The complex geometry of CSP resulted in the concentration of stress around CSP, and significantly undermines mechanical properties such as tensile strength and fatigue strength.
KW - Aluminum alloy
KW - Casting defect
KW - Die casting
KW - Fatigue
KW - Serial sectioning
KW - Shrinkage porosity
KW - X-ray computed tomography
UR - http://www.scopus.com/inward/record.url?scp=78049511645&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78049511645&partnerID=8YFLogxK
U2 - 10.2320/matertrans.MAW201032
DO - 10.2320/matertrans.MAW201032
M3 - Article
VL - 51
SP - 1574
EP - 1580
JO - Materials Transactions
JF - Materials Transactions
SN - 1345-9678
IS - 9
ER -