Al-Bi-Sn-(Cu)难混溶合金颗粒的核壳组织

Core-shell structure of Al-Bi-Sn-(Cu) Immiscible Alloys Particles

利用Al_(75)Bi_9Sn_(16)和(Al_(75)Bi_9Sn_(16))_(95)Cu_5难混溶合金,基于液相分离制备出了Al/Sn-Bi核壳型颗粒。采用SEM、EDS和DSC研究了颗粒的组织形貌、成分和相变行为。结果表明,合金颗粒以具有良好导电导热性的铝合金为内核、以Sn-Bi合金为壳层;添加Cu后,Cu主要存在于A1基内核中;Cu对壳层组织的Bi相有明显细化作用,含Cu合金颗粒壳层中Bi相尺寸仅为不含Cu合金的3/1;Cu的添加使Al_(75)Bi_9Sn_(16)合金的共晶反应和偏晶反应温度降低,而使液相分离温度增高。

Al/Sn-Bi core-shelled particles were prepared by phase separation of A175Bi9Sn16 and （Al75Bi9Sn16）95Cu5 alloy. The morphology, microstructure, composition and phase transformation of the core-shelled particles were investigated by scanning electronic microscopy, energy dispersive spectrometer and differential scanning calorimetry. It reveals that the particle comprises a shell of Sn-Bi alloy and a core of Al alloy with better electrical and thermal properties. Cu mainly exists in the Al-rich core with the Cu addition. The size of Bi phase in the shell of Cu containing-alloy particles is about only one third of that in the alloy without Cu, showing the significantly refining effect of Cu. The temperatures of eutectic and monotectic reactions decrease while the temperature of liquid phase separation increases with the Cu addition increasing.