Effectofannealingtreatmenton microstructure andpropertyofEr-containingAl-Mg-Znalloys

Effectofannealingtreatmentontensileproperties,intergranularcorrosion,macrostructure and microstructure of Al-6.0Mg-1.0Zn-0.8Mn-0.2Cu-0.2Er-0.1Zr hot-rolledplateasstudied by hardnesstesting,tensiletesting,intergranularcorrosion,OM,EBSD and TEM.Theresultsshow thatthestabilization work windowoftheplateis230 degrees C/18h,240 degrees C/6hand250-270 degrees C/2h.After 250 degrees C /2h,thealloyplatepresentsthebestcomprehensiveperformancewith263 MPayieldstrength and6.732 mg/cm2 massloss.250 degrees C/2hisselectedastheoptimalstabilizationprocessforhotrolled platebycombiningthemechanicalpropertiesandcorrosionresistance.Throughselectedareaelectron diffraction (SEAD)andenergyspectrum analysis,thesecondphaseatthegrainboundaryandinthe grainareallthe T-Mg32 (AlZn)49 phases.Afterannealingat250 degrees C/2 h,the T phasein grains graduallygrowsupandre-dissolves,andthe morphologychangesfrom squaretoshortrod.The T phaseare discontinuous and the spacing becomes larger at grain boundary,which shows good corrosionresistance.

Automated summary

The effect of annealing treatment on the tensile properties, intergranular corrosion, macrostructure, and microstructure of Al-6.0Mg-1.0Zn-0.8Mn-0.2Cu-0.2Er-0.1Zr hot-rolled plate was studied. The optimal stabilization process for the hot-rolled plate was determined to be at 250 degrees C for 2 hours, based on the mechanical properties and corrosion resistance. The TEM analysis revealed that the T phase within the grains gradually grew and re-dissolved after annealing, with a change in morphology from square to short rod. The T phase at the grain boundaries showed good corrosion resistance.