ISSN:
1573-4870
Keywords:
Pure magnesium
;
magnesium alloys
;
corrosion creep
;
borate buffer solution
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract A new synergistic effect of corrosion and stress on the viscoelasticity of pure magnesium and magnesium alloys has been shown. This phenomenon named corrosion creep has been studied in 99.9653% Mg, die-cast AZ91D (Mg–9% Al–1% Zn), AM50 (Mg–5% Al–0.4% Mn), and AS21 (Mg–2.3% Al, 0.23% Mn, 1.10% Si) alloys. Creep tests were carried out at 25°C in air and in the borate buffer aqueous solution (pH 9.3). It is found that the highest sensitivity to creep in the corrosive environment is observed in the alloy with the highest Al content. This agrees with the data obtained earlier in the study of mechanoelectrochemical behavior and corrosion fatigue of Mg alloys. However, in air, the creep behavior of all alloys at room temperature is approximately the same. Creep life of pure magnesium and its alloys significantly decreases in a corrosive environment. Corrosion-creep cracks filled with magnesium hydroxide particles were observed by SEM–EDS analysis at the surface of AS21 alloy. The thickness of the oxide layer defined by AES in samples of AZ91D, AM50, and AS21 alloys placed for 2 h into the borate solution amounts to ∼540, ∼1320, and ∼1440 nm, respectively. This can be explained with the account for surface phenomena.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1011399723559
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