Creep of medium and high strength aluminum alloys at normal temperature in moist atmospheres

Polyanskii, V. M.; Volkov, N. I.; Gorodkova, O. M.; Kopanov, Yu. N.; Frol'tsova, T. A.; Khailov, A. N.

doi:10.1007/bf00774981

Cited by 3 publications

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Inelastic CTSR is considered to include three components: strain rate due to time-dependent strain rate, _ ε (high-stress low-temperature creep 50 ), variations in applied load, _ e ε, and strain rate due to advance of a crack into the negative elastic-plastic strain gradient lying ahead of the advancing crack, _ ε 0 . Explicit representations 49,51 of these CTSR components are provided in the references.…”

Section: Crack Tip Strain Ratementioning

confidence: 99%

Synergism between fatigue and cyclic‐stress corrosion cracking: Electrochemically active surface area

Hall¹

2021

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

After over 50 years of research on the topic, researchers continue to consider how time-dependent environmental effects can be integrated with cycledependent fatigue crack growth rate (CGR) models. Early corrosion-fatigue (CF) model assumptions were that cycle-dependent CF and time-dependent stress corrosion cracking (SCC) contributions are separable, operate in parallel, are non-interacting. However, research has shown that CF and SCC may interact synergistically to produce CGRs greater than that obtained by simple summation. Proposed here is that CF and SCC mechanisms may interact synergistically as each is dependent on the electrochemically active surface area (E-ASA) at a crack tip. A phenomenological model is developed for the effects of crack tip strain rate, film-rupture, and repassivation rates on E-ASA. Analysis of hold-time CGR data provides a method of separating cyclic-and static-load hold-time effects on E-ASA. Five model parameters, each having physical interpretation, are found to have reasonable magnitudes.

show abstract

Section: Crack Tip Strain Ratementioning

confidence: 99%

Synergism between fatigue and cyclic‐stress corrosion cracking: Electrochemically active surface area

Hall¹

2021

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

show abstract

Delayed fracture and the nature of substructural defects formed in aluminum alloys due to sustained loading

Polyanskii¹,

Kurtasova²

1995

Mater Sci

View full text Add to dashboard Cite

Effect of cyclic frequency on fracture mode transitions during corrosion fatigue cracking of an Al-Zn-Mg-Cu alloy

Hall¹

2015

Corrosion Reviews

View full text Add to dashboard Cite

There are complex issues remaining to be resolved before environment-assisted cracking models can be included in structural mechanics programs that are currently used to analyze mechanical fatigue crack growth. Considered here is the effect of cyclic frequency on fracture mode transitions that occur during corrosion fatigue of high-strength Al-Zn-Mg-Cu alloys. These alloys are used in civilian and military aircraft applications where they are exposed to detrimental aqueous saline environments. A previously developed “critical hydrogen at a critical distance” crack growth model is used to rationalize the observed transitions in crack-path fracture-modes, from intergranular (IG), to brittle transgranular (BTG), to ductile transgranular (DTG), as the alternating stress intensity factor and cyclic frequency increase beyond critical values. Corrosion fatigue crack growth rate data obtained on Al-Zn-Mg-Cu alloy 7017-T651 base metal and heat-affected “white zone” metal tested in aqueous NaCl solutions over a frequency range of 0.01–70 Hz are analyzed. For the white zone metal, dependence of the critical crack velocity on the critical frequency, at which the IG-BTG transition occurs, undergoes an abrupt reversal as the critical frequency increases above about 0.1 Hz. Mechanisms potentially responsible for this change in frequency dependency are discussed in the context of the critical hydrogen model. The transition from low to intermediate frequency behavior is speculated to be due to a change in the critical distance from microstructural control, for frequencies at or below 0.1 Hz, to control by the critical hydrogen criterion at higher frequencies. The low frequency behavior is discussed relative to the transition from static load stress corrosion cracking to low frequency corrosion fatigue, which occurs as cyclic frequency increases above zero.

show abstract

Creep of medium and high strength aluminum alloys at normal temperature in moist atmospheres

Cited by 3 publications

References 3 publications

Synergism between fatigue and cyclic‐stress corrosion cracking: Electrochemically active surface area

Synergism between fatigue and cyclic‐stress corrosion cracking: Electrochemically active surface area

Delayed fracture and the nature of substructural defects formed in aluminum alloys due to sustained loading

Effect of cyclic frequency on fracture mode transitions during corrosion fatigue cracking of an Al-Zn-Mg-Cu alloy

Contact Info

Product

Resources

About