The statistic analysis of the effect of Ce content and pre-stretch suggests that there is a beneficial effect on
fracture toughness with large area fraction of combination of dimples and intermetallic particles, shown in
Fig.6. The area fraction of combination of dimples and intermetallic particles (Ad) are normalized by the T6 with
cerium content of 0.3% and T8 with cerium content of 0.15%, respectively.