Effect of B concentration on phase transformation in Fe-Zr-B amorphous alloys

Effect of B concentration on the thermal stability of amorphous phase and the crystallization process in Fe91-xZr9Bx (x = 0 to 30) alloys was examined. The onset temperature of crystallization (T-x) and glass formation temperature (T-g) monotonously increased with increasing B concentration, while the temperature interval of the supercooled liquid region ( Delta T-x -T-g-T-x) rapidly increased with B concentration up to 20.0 at.%B reaching about 70K. Fe71Zr9B20 alloy having the widest supercooled liquid region in present study showed four stages in crystallization. TTT diagram of Fe71Zr9B20 alloy was determined for the phase transformation from amorphous or supercooled liquid states to alpha-Fe and several compounds and sequential changes of crystalline phases. The crystallization behavior differed from that of Fe88Zr9B3 alloy that forms nanocrystalline structure by first crystallization.