氧对Zr-Cu-Ni-Al-Ti块体非晶合金热稳定性的影响

EFFECT OF OXYGEN ON THE THERMAL STABILITY OF Zr-Cu-Ni-Al-Ti BULK AMORPHOUS ALLOY

以结晶Zr棒及海绵Zr为原材料、利用浇包型坩埚电弧炉倾斜铸造法制备了不同氧杂质含量的Zr_(52．5)Cu_(17．9)Ni_(14．6)Al_(10)Ti_5块体非晶合金楔形试样,研究了氧对合金玻璃形成能力及热稳定性的影响,结果表明：氧杂质虽然降低合金以最大非晶形成厚度t_(max)为表征的玻璃形成能力,却提高合金以过冷液相区温度范围△T_(x1)为表征的热稳定性,氧杂质具有提高合金开始晶化表观激活能E_(ax1)的趋势。

Crystal Zr bar and sponge Zr were employed as raw materials to prepare wedge-like specimens of Zr52.5Cu17.9Ni14.6Al10Ti5 bulk amorphous alloy with different oxygen impurity contents by a tilt casting method using ladle hearth type arc furnace. Effects of oxygen impurity on the alloy＇s glass forming ability and thermal stability were investigated. It is shown that the glass forming ability of the quinary alloy characterized by maximum amorphous sample forming thickness tmax Was decreased as oxygen impurity content increased, on the contrary, its thermal stability characterized by supercooled liquid region △T×1 was enhanced. Oxygen impurity has the tendency to heighten the apparent activation energy Ea×1 for the crystallization process onset of the amorphous alloy, which made the crystallization incubation period of the alloy under larger supercooled state lengthened and thereby the thermal stability enhanced.