Microstructural evolution and flow behaviour in hot compression of as-extruded Mg-Gd-Nd-Zn-Zr alloy

Hot deformation behaviour of as-extruded Mg-5Gd-2.5Nd-0.5Zn-0.5Zr alloy was investigated using compression test at a temperature range of 350-500 degrees C and strain rates of 0.001-1 s(-1). Microstructural evolution of cast and homogenised alloy following high-temperature deformation was captured by optical and scanning electron microscopy. Energy dispersive spectrometer results indicated that cast and homogenised samples consisted of eutectic compositions were mainly enriched in Nd and Gd. The flow stress was fairly well fitted by the hyperbolic sine equation where the calculated average activation energy was 297.81 kJ/mol. Hot deformation of the alloy was strongly affected by the high rare-earth metal (RE) constituent, and manifested by twining phenomenon at a temperature below 350 degrees C and by dynamic recrystallization (DRX) and DRX-second phase interaction above 350 degrees C.

Automated summary

The hot deformation behavior of Mg-5Gd-2.5Nd-0.5Zn-0.5Zr alloy was investigated through compression tests at temperatures ranging from 350 to 500 degrees C and strain rates from 0.001 to 1 s(-1). Microstructural evolution showed a high rare-earth metal constituent affecting the deformation mechanisms, including twining below 350 degrees C and dynamic recrystallization and second phase interaction above 350 degrees C. The flow stress was well fitted by the hyperbolic sine equation with an average activation energy of 297.81 kJ/mol.