【摘要】 金属熔体的形核过程是影响其凝固组织与性能的主要因素，实际的金属凝固过程多为异质形核，异质形核的难易程度则主要由形核界面决定。采用磁控溅射技术制备非晶Si薄膜，然后利用纳米量热仪研究了纯Sn微滴在此衬底上的凝固形核特性。结果表明：Sn微滴的形核表现出了明显的随机性，在1×10⁴ K/s的扫描速率下，形核过冷度在106～114 K之间。基于经典形核理论和Poisson统计分析方法，研究了单个Sn微滴在非晶Si衬底上的形核动力学，获得形核接触角约为77°,表明非晶Si衬底不利于Sn微滴的凝固形核。更多还原

【Abstract】 Nucleation process of metal melt is the main factor affecting its solidification microstructure and properties, the actual solidification process of metal liquid is mostly heterogeneous nucleation, and whether the heterogeneous nucleation is difficulty is mostly dependent on the nucleation interfaces. The amorphous Si thin-film was prepared by magnetron sputtering deposition technique, and then the nucleation behavior of a pure Sn droplet on Si thin-film substrate during solidification was studied by nanocalorimetry. The results showed that the nucleation of Sn droplets showed obvious randomness, and under the scanning rate of 1×10~4 K/s, the nucleation undercooling ranged from 106 to 114 K. The nucleation kinetics of a single Sn droplet on amorphous Si substrate was studied on the basis of classical nucleation theory and Poisson statistical analysis method, and the contact angle was about 77°, indicating the amorphous Si substrate was not conducive to the solidification and nucleation of Sn droplets.更多还原