Al基Al-V中间合金制备过程中含V相的演变

Evolution of V-containing phases during preparation of Al-based Al−V master alloys

由于熔炼和凝固过程显著影响含V相的结构演变,而不同含V相后续又会影响工业铝合金和钛合金的组织和性能,因此,本文作者基于升温熔炼和降温熔炼实验,结合快速凝固制备Al基Al-V中间合金,研究不同Al-V合金中含V相的相变规律。研究结果表明,Al-50wt.%V合金原料由针状Al_(3)V相和Al_(8)V_(5)基体相组成,而后续制备所得的Al-V中间合金由花瓣状Al_(3)V相、针状Al_(7)V相和片状Al_(10)V相构成。由Al_(3)V相转变而来的针状亚稳Al_(7)V相将进一步转变为片状Al_(10)V相。Al_(10)V相数量随熔炼温度(800~1000℃)的降低而增大。花瓣状Al_(3)V相可由Al_(8)V_(5)相转变而来,在熔炼过程中从Al-V熔体中预析出以及在合金凝固过程中析出形成。

Al-based Al−V master alloys were prepared by both the stepwise heating melting experiment and stepwise melting cooling experiment with rapid solidification to investigate the transformation of V-containing phases which gave different effects on microstructures and properties of commercial Al alloys and Ti alloys,as both melting and solidification processes affect the evolution of V-containing phases largely.The results showed that the raw Al−50wt.%V alloy consisted of needle-like Al_(3)V phase and Al8V5 phase(matrix),while petal-like Al_(3)V,needle-like Al_(7)V and plate-like Al_(10)V phase were present in the Al−V master alloys.The metastable Al_(7)V phase was evolved from Al_(3)V phase and then evolved into Al_(10)V phase during melting process.The number of Al_(10)V phase increased with the decrease of temperature in the range of 800−1000℃.Petal-like Al_(3)V phases could be transformed from Al_(8)V_(5) phase,pre-precipitated from Al−V molten liquid during melting process and precipitated directly during rapid solidification,respectively.