Corrosion fatigue crack growth behavior of a squeeze-cast Al-Si-Mg-Cu alloy with different precrack histories

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-997-0209-0· OSTI ID:522360

Shiozawa, Kazuaki; Sun, Shuming ^[1]

---

1. Toyama Univ. (Japan). Dept. of Mechanical Systems Engineering

Fatigue experiments have been performed on a squeeze-cast Al-Si-Mg-Cu alloy as a function of precrack history. The precracked conditions were that the compact tension specimen was precracked with a relatively long-through-thickness crack (about 6 mm) in air, in aqueous 3 pct NaCl solution, and in air followed by hydrogen precharging. It was found that a relatively long through-thickness crack can grow more rapidly than would be predicted by a traditional {Delta}K involving three stages under either a corrosion fatigue test after precracking in air or a hydrogen precharging experiment followed by fatigue testing in air. The experimental evidence confirms that a hydrogen-assisted damage mechanism is mainly responsible for the rapid growth phenomenon of a relatively long crack in a corrosive environment compared to the result of fatigue testing in air after hydrogen precharging. The amount of hydrogen production in chemical-microstructure interaction processes in a corrosion fatigue experiment and the effectiveness of hydrogen transport to the region ahead of the crack tip determine the degree of hydrogen-assisted fatigue crack growth, which is controlled by the microstructure of the alloy and the chemical attack on a sharp and fresh crack tip.

• Sponsoring Organization: USDOE
• OSTI ID: 522360
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 7 Vol. 28; ISSN 1073-5623; ISSN MMTAEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AIR
ALUMINIUM ALLOYS
COPPER ALLOYS
CORROSION FATIGUE
CRACK PROPAGATION
CRACKS
HYDROGEN EMBRITTLEMENT
KINETICS
MAGNESIUM ALLOYS
SILICON ALLOYS
SODIUM CHLORIDES