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The non-isothermal and isothermal crystallization kinetics of Zr_(72.5)Al_(10)Fe_(17.5) glassy alloy was investigated using differential scanning calorimeter(DSC).Under non-isothermal heating condition,the primary phase in the initial crystallization is Zr_6Al_2Fe phase and the final crystallized products consist of Zr_6Al_2Fe,Zr_2Fe and a-Zr phases.The apparent activation energy for crystallization estimated using the Kissinger method is 342.1 ±8.1 kJ/mol.The local activation energy decreased with the increase in the crystallization volume fraction during nonisothermal crystallization.Under isothermal heating condition,the average Avrami exponent of about 2.76 implies a mainly diffusion-controlled three-dimensional growth with an increasing nucleation rate.The local activation energy for isothermal crystallization shows a different variation trend from that for nonisothermal crystallization,indicating different nucleation-and-growth mechanisms for the two crystallizaiton conditions.
The non-isothermal and isothermal crystallization kinetics of Zr_ (72.5) Al_ (10) Fe_ (17.5) glassy alloy were investigated using differential scanning calorimeter (DSC) .Under non-isothermal heating condition, the primary phase in the initial crystallization is Zr_6Al_2Fe phase and the final crystallized products consist of Zr_6Al_2Fe, Zr_2Fe and a-Zr phases. The apparent activation energy for crystallization estimated using the Kissinger method is 342.1 ± 8.1 kJ / mol.The local activation energy decreased with the increase in the crystallization volume fraction during nonisothermal u.n. isothermal heating condition, the average Avrami exponent of about 2.76 implies a major diffusion-controlled three-dimensional growth with an increasing nucleation rate. the local activation energy for isothermal crystallization shows a different variation trend from that for nonisothermal crystallization, indicating different nucleation-and-growth mechanisms for the two crystallizaiton conditions.