基于快速热分析技术的Al基体中InSn合金液滴的凝固特性研究

Study on Solidification Behavior of InSn Droplets Embedded in Aluminum Matrix by Fast Scanning Calorimetry

利用单辊旋淬法制备了镶嵌有大量纳米InSn合金液滴的铝合金薄带,并利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对合金薄带的物相组成和显微形貌进行了系统的表征。结果表明:薄带样品中InSn合金液滴有两种存在形式:一种是镶嵌在Al晶粒内部的大量纳米尺寸的InSn合金颗粒,另一种是分布于晶界的微米尺寸的InSn合金液滴。In和Sn发生共晶反应生成两种物相,分别是In3Sn和InSn4相。此外,利用快速热分析仪(FSC)研究了镶嵌在Al基体中InSn合金液滴的凝固及熔化特性。结果发现:单一吸热峰的温度接近于InSn共晶的熔化温度,在冷却过程中还存在一个放热峰,当冷却速率达到10^4K/s时,凝固过冷度最大为21K。

Aluminum alloy ribbons in which a large number of nano-sized InSn alloy droplets was embedded were prepared by rotational quenching technique on a single roller.And the phase compositions and microstructures of the alloy ribbon were systematically characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results showed that there were two kinds of InSn droplets existed in the Al matrix:one was a large number of nano-sized InSn droplets embedded within the Al grains,and another was the micro-sized InSn droplets distributed at the grain boundaries.In and Sn underwent eutectic reaction to form two phases,namely In 3Sn and InSn 4 respectively.In addition,the melting and solidification of InSn alloy droplets embedded in the Al matrix were studied by fast scanning calorimetry(FSC).It was found that the temperature of single endothermic peak was close to the melting temperature of the InSn eutectic alloy,and there existed an exothermic peak in the cooling process.The maximum undercooling degree of InSn droplets was 21 K when the cooling rate was 10^4 K/s.