Sc对Zr基块体非晶合金晶化动力学的影响

以海绵锆为原材料,利用浇包型坩埚电弧炉倾斜铸造法制备Zr52.5Cu17.9Ni14.6Al10Ti5五元块体非晶合金楔形试样,研究活性元素Sc对合金玻璃形成能力及晶化动力学参数的影响。结果表明:Sc的加入可显著增大合金的最大非晶形成厚度,但对合金过冷液相区温度范围所表征的热稳定性影响较小。Sc虽然使合金的晶化激活能降低,但使晶化孕育期时间常数增大,晶化频率因子减小,二者的综合作用使合金晶化孕育期延长,过冷倾向增大,玻璃形成能力提高。

Effect of Sc on crystallization kinetics of Zr-based bulk amorphous alloy

Sponge zirconium was employed as raw material to prepare wedge-like specimens of Zr_(52.5)Cu_(17.9)Ni_(14.6)Al_(10)Ti_5 quinary alloy by a tilt casting method using ladle-hearth-type arc furnace.The effect of active element Sc on the glass forming ability and crystallization kinetic parameters of the quinary alloy is investigated.It is shown that the maximum amorphous forming thickness of the alloy was increased greatly because of the addition of Sc,however,the thermal stability characterized by supercooled liquid region is hardly affected.Although the apparent activation energy for crystallization process is decreased after Sc addition,the incubation period constant is enlarged and the frequency factor is reduced.The synthetical influence of these two aspects makes the incubation period prolonged,supercooled tendency increased and therefore glass forming ability improved.