The effect of Laves phases and nano-precipitates on the electrochemical corrosion resistance of Mg-Al-Ca alloys under alkaline conditions  

作　　者：Markus Felten Veronika Chaineux Siyuan Zhang Ali Tehranchi Tilmann Hickel Christina Scheu Joshua Spille Marta Lipińska-Chwałek Joachim Mayer Benjamin Berkels Marcus Hans Imke Greving Silja Flenner Sandra Sefa Daniela Zander 

机构地区：[1]Chair of Corrosion and Corrosion Protection,RWTH Aachen University,Aachen 52072 Germany [2]Max-Planck-Institut für Eisenforschung GmbH,Düsseldorf 40237 Germany [3]Central Facility for Electron Microscopy,RWTH Aachen University,Aachen 52074 Germany [4]Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons,Forschungszentrum Jülich GmbH,Jülich 52428,Germany [5]Mathematical Image and Signal Processing,Aachen Institute for Advanced Study in Computational Engineering Science,RWTH Aachen University,Aachen 52062 Germany [6]Materials Chemistry,RWTH Aachen University,Aachen 52074 Germany [7]Institute of Materials Physics,Helmholtz-Zentrum Hereon,Geesthacht 21502 Germany

出　　处：《Journal of Magnesium and Alloys》2024年第6期2447-2461,共15页镁合金学报（英文）

基　　金：the financial support of the Deutsche Forschungsgemeinschaft(DFG)of the Collaborative Research Center(CRC)1394“Structural and Chemical Atomic Complexity-from defect phase diagrams to material properties”–project ID 409476157;the Excellence Strategy of the Federal Government and the L?nder project IDG:(DE-82)EXS-SF-OPSF596。

摘　　要：The electrochemical corrosion mechanisms of Mg alloys were extensively studied in previous investigations of different chemical com-positions,modified surface states and various electrolyte conditions.However,recent research focused on the active state of Mg dissolution,leading to unresolved effects of secondary phases adjacent to a stableα-solid solution passive layer.The present study investigates the fundamental electrochemical corrosion mechanisms of three different Laves phases with varying phase morphologies and phase fractions in the passive state of Mg-Al-Ca alloys.The microstructure was characterized by(transmission-)electron microscopy and synchrotron-based transmission X-ray microscopy.The electrochemical corrosion resistance was determined with a standard three-electrode setup and advanced in-situ flow cell measurements.A new electrochemical activity sequence(C15>C36>α-Mg>C14)was obtained,as a result of a stable passive layer formation on theα-solid solution.Furthermore,nm-scale Mg-rich precipitates were identified within the Laves phases,which tend to inhibit the corrosion kinetics.

关 键 词：Laves phase STEM MAGNESIUM Corrosion Passive layer 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG172[金属学及工艺—金属材料]