摘要
Mg-0.5Bi-0.5Sn alloys with and without microalloying with 0.5 wt%Mn were subjected to extrusion,and the effect of Mn microalloying on the microstructural characteristic and corrosion behavior of the extruded alloys was investigated.The results indicated that the average grain size and the density of dislocations decreased,and a new Mg_(26.67)Mn_(65.47)Fe_(7.86)second phase as well as grain boundary segregation of Sn atoms could be observed in certain micro-regions of the extruded dilute Mg-0.5Bi-0.5Sn-0.5 Mn alloy.The tailoring of microstructure resulted in the significant enhancement in corrosion resistance(R_(p)increased from 1095.91Ωcm^(2)to 5008.79Ωcm^(2)).In addition,grain boundary segregation resulted in intergranular corrosion and led to the dissolution of Sn atoms.Hence,the dissolution rate of the matrix in Mg-0.5Bi-0.5Sn-0.5Mn alloy could be inhibited by the corrosion product film containing an intermediate product(SnO_(2)).
基金
jointly supported by the National Natural Science Foundation of China(Grant nos.:51704209,51701060)
Natural Science Foundation of Shanxi Province(Grant no.:201801D121088)
Shanxi Province Science Foundation for Youths(Grant no.:2016021063)
Shanxi Scholarship Council of China(Grant no.:2019032)
the Science and Technology Major Project of Shanxi Province(Grant nos.:20191102008,20191102007)。
