Mechanical and corrosion properties of biodegradable Mg-1.5Mn-1Ca-xSr alloys

摘要

The mechanical properties and corrosion mechanism of both as-cast and solution-naturally age (T4) treated Mg-1.5Mn-1Ca-xSr alloys were investigated. The results showed that Sr is helpful to decrease grain size and increase the strength. The corrosion process of alloys was mainly determined by the quantity and distribution of second phases. Mg_(17)Sr2, α-Mn and Ca-Sr phases acted as cathodes accelerated the corrosion of Mg2Ca anodic phase and α-Mg matrix. However, continuous distributed Mg_(17)Sr2 was beneficial to resist the happening of localized corrosion because of its barrier effect. T4 treatment could significantly improve the mechanical properties and corrosion resistance of Mg alloys because of the dissolution of Mg2Ca phase and the dispersive distribution of Mg_(17)Sr2 and a-Mn phases.