Crack Paths 2009

facets can be related to the load period and as a consequence to the crack growth

enhancement during cyclic loading at low frequencies for a given environment.

d

10 -4 -3

6 8 10

10s-03s0-01s0-s10s 1350s-10-s10s

30

50 70

d

10s-03s0-s01-s01-s01s0s 15 -10s

c le )

c le )

10-87 -65

(m / c y

(m / c y

a / d N

a / d N

127R65=5°0C.TA5i6r

( M P a x m 1/2 )

100-87 -654 10 3

123R60=5°0C.TA5i6r

6 8 10

30

50 70

K m a x ( M P a m 0,5 )

K m a x

(a)

(b)

Figure 7: Influence of hold time on creep-fatigue crack growth rates at R=0.5 (a) at

130°C; (b) at 175°C.

(a)

(b)

(c)

Figure 8: fracture surfaces produced during (a) C C G(K=22 M P ax m1/2 , 175°C), (b)

C F C G(Kmax= 23 M P a x m1/2, da/dN = 2x10-5 m/cycle, 10s-1500s-10s, 175°C) (c)

cavitation at triple grain boundary (Kmax= 30 M P a x m1/2 , da/dN = 2x10-6 m/cycle, 10s

300s-10s, 175°C).

R E F E R E N C E S

1. Menan, F. and Henaff, G. (2009) International Journal of Fatigue in press.

2. Menan, F. (2008) Influence de la Corrosion Saline sur la Tolérance aux Dommages

d'un Alliage d'Aluminium Aéronautique 2XXX, PhD thesis, University of Poitiers,

France: Futuroscope Chasseneuil.

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