| Title |
Research Paper - Transformations - : The Effect of N2 and Ar Atmosphere on Phase Formation and Magnetic Properties of Mechanical Alloyed Fe - Zr Powder |
| Authors |
이성의(S . E . Lee); 나형용(H . Y . Ra); 김원태(W . T . Kim); 임태홍(T . H . Yim) |
| Abstract |
The effect of surrounding atmosphere on phase changes during mechanical alloying of Fe-Zr was studied by X-ray diffractometry, transmission electron microscopy and magnetometry. Atmosphere during mechanical alloying was controlled by using either nitrogen or argon gas. Mechanically alloyed Fe-Zr powders showed a mixture of amorphous phase and α-Fe phase. Amorphization during mechanical alloying in nitrogen atmosphere was retarded compared with mechanical alloying in argon atmosphere. Fraction of α-Fe phase was higher in the alloy powders processed in nitrogen atmosphere than in alloy powders in Ar. The retardation of amorphization during mechanical alloying in nitrogen may be attributed to hardening of Fe phase by the increase of N solubility, which results in difficulty of plastic deformation of Fe phase. Variation of magnetization with processing time agrees well with the structural change with processing time. With increasing processing time, magnetization of Fe-Zr alloys processed in argon decreased rapidly due to the formation of amorphous phase, reached a steady values. Variation of magnetization of Fe-Zr powders processed in nitrogen atmosphere was not significant due to the retarded amorphization. Alloy powders processed in nitrogen atmosphere showed higher magnetization than the powders in Ar atmosphere. |