The growth of α-Fe(Si) nanocrystalline grains as a function temperature in amorphous Fe76.5-xNbxCu1Si13.5B9 (x=1, 3, 5, 7) alloys and study their hardness. AIUB Journal of Science and Engineering (AJSE), v. 24, n. 2, p. 98–106, 31 May2026.