Glass-Forming Ability for Mg-Cu-Nd Alloys

The glass-forming ability (GFA), thermal stability, and mechanical properties of ternary Mg-Cu-Nd alloys were investigated. The results show that the amorphous structure of about 3 mm in diameter can be obtained in the composition range of 53 to 59 at. pct Mg, 32 to 38 at. pct Cu, and 9 to 11 at. pct Nd. Differential scanning calorimeter (DSC) measurements show that the bulk metallic glasses (BMGs) exhibit distinct glass transition temperature and supercooled liquid region before crystallization. However, the GFA for the present alloys cannot be explained by the existing calculated parameters, while it can be better explained by the strategy for pinpointing the best glass-forming alloys in terms of microstructure evolution. Compared with Mg₅₇Cu₃₃Y₁₀ BMG, Mg-Cu-Nd BMGs show a better fracture strength, which is increased with the copper content for those Nd-containing BMGs. Viscous flow was observed on the fracture surfaces of compressive samples, showing that apparent strengths can be reproducible. The Mg-Cu-Nd BMGs are challengeable in potential application for engineering materials due to their high strength and low cost. This article is based on a presentation given in the symposium entitled “Bulk Metallic Glasses IV,” which occurred February 25–March 1, 2007 during the TMS Annual Meeting in Orlando, Florida under the auspices of the TMS/ASM Mechanical Behavior of Materials Committee.