Effects of calcium concentration on room temperature formability and damping properties of rolled Mg-Ca alloys

Abstract

In this study, rolled MgCa alloys were processed by hightemperature preannealing at 500℃ and subsequent warm rolling at 200℃. The rolled alloys processed by repetition of the above rolling procedure were finally annealed at 350℃. This process was effective rolling procedure for suppression of basal texture formation of MgMn and MgCe alloys. The rolled Mg0.1Ca alloy exhibited a significantly increased Erichsen value of 7.1, which was much larger value compared with commercial Mg alloys. On the other hand, excessive calcium addition more than 0.3 mass％ deteriorated room temperature formability. Basal texture intensity of MgCa alloys had much smaller value, when calcium concentration was set more than 0.1 mass％, indicating that the suppression of basal texture formation mainly contributed to the enhanced stretch formability of Mg0.1Ca alloy. The deteriorated formability of Mg0.3Ca alloy was attributed to the formation of coarse precipitates in the alloy. Retardation of dynamic recrystallization during warm rolling was suggested to be one of the reason for suppression of strong basal texture formation for MgCa alloy, when calcium concentration was set to more than 0.1 mass％. The internal friction of the Mg0.1Ca alloy was found to be almost the same as that of pure magnesium at certain strain amplitude.