ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The objective of this study is to quantify and understand the effectiveness of a hexavalent chromereplacement ion to inhibit environmentally assisted fatigue crack propagation (EFCP) in high strengthaluminum alloys. Addition of molybdate (MoO42-) to bulk-low chloride solution effectively inhibitsEFCP in peak aged 7075, comparable to that of CrO42-. The effectiveness of inhibition depends stronglyon loading variables: .K, R, and frequency as explained qualitatively by mechanical instability of acrack tip passive film that otherwise hinders production and uptake of embrittling hydrogen. The criticalloading frequency (and crack tip strain rate), below which film stability and inhibition occur, increaseswith increasing inhibitor concentration, but only for low stress ratio loading, perhaps due to occludedcrack transport and reaction considerations. Molybdate could be a beneficial replacement for chromateand a candidate for inhibitor release from a tailored coating
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/54/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.345-346.989.pdf
Permalink