| Title |
Glass Forming Ability and Thermal Stability in Fe-P-C-B Alloy System |
| Authors |
국진선(Jin Sun Gook) ; 진영철(Yeog Cheol Jin) ; 전우용(Woo Yeoung Chon) ; 이민호(Min Ho Lee) |
| Abstract |
The glass forming ability and thermal stability has been investigated in Fe-P-C-B alloy system. The glassy allay containing 10-12at%P, 4-6at%C or 4-6at%B in the Fe_(80-x·y·z)(P_xC_yB_z)_(20) system was found to cause the extension of the supercooled liquid region, ΔT_x(=T_x-T_g) defined by the difference between crystallization temperature(T_x) and glass temperature(T_g) to 30K. The increase of ΔT_x is due to the increase of T_x exceeding the degree of the increase of T_g. The crystallization progress of the glassy alloys with ΔT_x about 30K takes place through a single stage of amorphous(Am)→(α-Fe + Fe₃P + Fe₃C + Fe₃B). On the other hand, the two stage process cause the disappearance of the glass transition phenomenon before crystallization. The reason for the high thermal stability of the supercooled liquid region and large glass-forming ability for the Fe-P-C-B alloy is interpreted to result from the combination of the following two contributions : (i) the suppression of crystalline nuclei due to the increase in the degree of dense random packed structure resulting from the significant difference in atomic sizes among P, C and B, (ii) the difficulty of the atomic rearrangements for the percipitation of the Fe-metalloid compounds. |