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°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°C and by dynamic recrystallization (DRX) and DRX-second phase interaction above 350°C.
