| Title |
Pesearch Paper / Transformations : Amorphous Phase Formation of Zr65Al7.5Ni10Cu17.5 Alloy Powder Fabricated by Gas Atomization |
| Authors |
임경묵(K . M . Lim),김형준(H . J . Kim),김연욱(Y . W . Kim),박찬경(C . G . Park) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
The amorphization behavior of a Zr_(65)A_(7.5)Ni_(10)Cu_(17.5) alloy powder fabricated by a vacuum gas atomization has been investigated in this study. The thermal stability of the present alloy powder was investigated using DTA, and was compared with that of the bulk amorphous alloy produced by casting. The ΔT_x(T_x-T_g) value of the amorphous powder was is smaller than that of the bulk amorphous alloy. This decrease in thermal stability was due to the two-step crystallization process of the amorphous phase. Each particle of the alloy powder was solidified to either fully amorphous phase or fully crystalline phase, indicating that the crystallization behavior of this powder was highly dependent on the isolation effect. Fully vitrified powder could be obtained when the powder size was below 45㎛. As the powder size increased, the fraction of the amorphous powder decreased. From these results, it is considered that the control of heterogeneous nucleation sites such as impurities and oxides is very important factor of amorphization of the present alloy powder. |