000 01691nab a2200181 4500
005 20260520001103.0
008 260224s2012 xxu
245 0 0 _aInfluence of lead on the microstructure and corrosion behavior of melt-conditioned, twin-roll-cast AZ91D magnesium alloy
260 _a
_b
_cjun. 2012
270 _a06/09/2012 ; 06/09/2012
300 _a9 p. ; 548-556
520 _aThe influence of lead addition on the microstructure and the corrosion behavior of a melt-conditioned, twin-roll-cast (MCTRC) AZ91D magnesium alloy has been investigated. Electron probe microanalysis revealed that lead-containing (magnesium plumbide [Mg2Pb]) particles were formed in the alloy and were concentrated mainly at the interdendritic boundaries. Scanning Kelvin probe force microscopy indicated increased surface potentials for the Al-Mn intermetallics, the Pb-rich particles, and the ß phase, relative to the adjacent a-Mg matrix, suggesting their greater nobilities with respect to the a-Mg matrix. Corrosion testing revealed that the corrosion initiated at the a-eutectic/lead-containing particle and a-eutectic/Al-Mn particle interface, as a result of galvanic coupling between the intermetallics and a-eutectic. Corrosion subsequently propagated into the primary a-Mg matrix. The ß-Mg17Al12 phase network at the grain boundaries acted as a corrosion barrier, restricting the propagation of corrosion from one grain to an adjacent grain, thereby contributing to an improvement in the corrosion resistance of the MCTRC AZ91D magnesium alloy.
581 _a6
773 0 _tCorrosion
_g68
942 _cARTICULO
100 1 _aPawar, S.
_952638
999 _c187304
_d187304