Zr-Ti-Cu-Ni-Be大块非晶合金等温晶化过程相分离研究

Phase Separation of Zr-Ti-Cu-Ni-Be Bulk Amorphous Alloy during Isothermal Annealing

利用差示扫描量热法(DSC)和透射电镜(TEM)对 Zr41.2Ti13.8Cu12.5Ni10Be22.5 (at%)大块非晶合金的等温晶化 过程和析出相进行了研究。结果表明,大块非晶合金在等温晶化过程中表现出多阶段相析出行为,并且在不同的晶化 阶段,析出相也有所不同。在第 1 个晶化阶段,析出相主要是体心四方(b.c.t)结构的 Zr2Cu 相;而在晶化的第 2 个阶段,晶化相主要为简单六方结构的 ZrBe2相。从一定程度上证实了 Zr41.2Ti13.8Cu12.5Ni10Be22.5大块非晶合金在发生晶化时 会形成富 Zr 区和富 Be 区,即有相分离的趋势。XRD 测试的结果也证实了非晶合金在发生完全晶化时,主要的晶化产 物为 Zr2Cu 和 ZrBe2相。

Employing differential scanning calorimetry (DSC) and transmission electron microscopy (TEM), the isothermal crystallization process and precipitated phases of Zr41.2Ti13.8Cu12.5Ni10Be22.5 (at%) bulk amorphous alloy were investigated. It is found that the bulk amorphous alloy exhibited a multi-stage crystallization behavior when being isothermal annealed. The precipitated phases are different at various crystallization stages. The experiment results show that the main precipitation phase is body-centered tetragonal (b.c.t) Zr2Cu at the first crystallization stage but primitive hexagonal ZrBe2 at the second stage, confirming that the Zr41.2Ti13.8CU12.5Ni10Be22.5 bulk amorphous alloy possesses a phase separation tendency during the isothermal annealing processes. The X-ray diffraction (XRD) result validated that the main precipitation phases were Zr2Cu and ZrBe2 when the bulk amorphous alloy was fully crystallized.