Droplet Segregation in Miscibility-Gap Alloy Solidification Owing to Thin Film Effects

本文旨在阐明混相GaP合金凝固过程中薄膜效应所产生的粗化效应。NSF寻求的资金将支持联合实验/分析调查的实验阶段，其中分析部分由NASA提供支持。在实验研究中，将利用梯度台显微镜设备，通过透明池通过视频成像来实现丁二腈-榄烯体系的定向凝固。这将提供有关通过推进凝固前沿对超细颗粒和液滴的排斥和捕获的重要信息。利用Rame-Hart吊坠装置，将测量组件的界面张力。获得的数据将用于验证NASA资助下开发的分析模型。特别是，验证将取决于对临界液滴大小的预测，以及根据视频成像数据确定的被推进的凝固前沿拒绝的最大液滴的测量。这项工作将为定向凝固过程中液滴的排斥提供第一个实验数据。所有先前的研究都涉及到固体颗粒排斥。

This proposal seeks to elucidate the coarsening effects in miscibility-gap alloy solidification owing to thin-film effects. The NSF funding sought will support the experimental phase of a joint experimental/analytical investigation where the analytical part is being supported by NASA. In the experimental study, the directional solidification of the succinonitrile-camphene system via video imaging through a transparent cell utilizing a gradient stage microscope facility will be done. This will provide important information on the repulsion and capture of ultra-fine particles and droplets by advancing solidification fronts. Utilizing a Rame-Hart pendant drop apparatus, component interfacial tensions will be measured. The data obtained will be used to validate the analytical model being developed under NASA funding. In particular, validation will hinge on predictions of the critical droplet size with measurements of the largest droplets rejected by the advancing solidification front determined from the video imaging data. This work will provide the first experimental data for droplet rejection in directional solidification. All prior studies involved solid particle rejection.