Nitrogen-doping effect on glass formation and primary phase selection in Cu–Zr–Al alloys

Effects of nitrogen doping on the glass formation and primary precipitate phase in a ternary Cu–Zr–Al alloy were investigated. An optimized doping level of nitrogen (∼1000 appm) can improve the glass-forming ability of Cu49Zr44Al7 alloy. The type of primary phases from ZrCu (B2) to an unknown Zr- and Al-rich crystalline phase with chemical atomic composition of around Cu38Zr49Al13 in the bulk glassy matrix is controllable by the micro-adjustment of N concentration, which can be utilized as an effective way to design BMG-based composites with selective second phase particles.

Research highlights
► Optimal nitrogen doping enhances the glass-forming ability of Cu49Zr44Al7 alloy.
► Trace N controls the type of primary precipitate phase during solidification.
► The study provides new candidates for the alloying of BMGs in improving GFA.
► The study provides effective way in designing BMG composites with selective phase.