Temperature dependence of resistivity and crystallization behaviors of amorphous melt -spun ribbon of Mg66Zn30Gd4 alloy

摘要

In this paper, the Mg-based Mg(66)Zn(3)oGd(4) amorphous ribbons were successfully prepared using a single roller melt-spinning technique. Subsequently, the non-isothermal crystallization behaviors of alloy ribbons were investigated by differential scanning calorimetry (DSC) and resistivity method, and its crystallization process and microstructure were confirmed by X-ray, transmission electron microscope (TEM) and selected area electron diffraction (SAED). The results show that: the negative temperature coefficient of resistivity (TCR) exists in the crystallization process, and the crystallization process of melt-spun Mg(66)Zn(3)oGd(4) ribbons consists of three steps. The first crystallization reaction at about 385 K is connected with the formation of the ICQ-phase, followed by the formation of the Mg7Zn3 binary phase and the Mg-3(Gd, Zn) ternary phase (468-538 K), and then the formation of the alpha-Mg phase at about 538 K. Furthermore, the formation of the ICQ-phase reflects the heredity of icosahedral local order.