Abstract: The glass-forming ability (GFA) of Nd70-xFe20Al10Yx and Nd60-xFe30Al10Yx (0≤x≤15) alloys produced by Cu mold casting was investigated. Except Y=5 at.pct, bulk amorphous Nd70-xFe20Al10Yx alloys up to 2 mm in diameter were obtained. The GFA for Nd60-xFe30Al10Yx alloys, however, was found to decrease with increase of Y due to the increasing compositional deviation from the original eutectic point of Nd60Fe30Al10 alloy. The Nd60Fe20Al10Y10 and Nd60Fe30Al10 alloy exhibit the largest GFA and can be cast into bulk amorphous cylindrical specimens of 3 mm in diameter. The melting temperature or/and the reduced crystallization temperature is closely related to the GFA of Y-containing alloys. The bulk amorphous cylinder for the Nd55Fe20Al10Y15 alloy shows a distinct glass transition temperature and a wide supercooled liquid region before crystallization. The crystallization temperature, Tg, and the supercooled liquid region, ∆Tx, are 776 K and 58 K, respectively. The GFA and thermal stability of the Nd-Fe-Al-Y alloys were discussed.

Key words: Nd-based alloys, Glass forming ability, Liquidus temperature, Thermal stability