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

本文旨在阐明由于薄膜效应导致的混相间隙合金凝固过程中的粗化效应。所寻求的NSF资金将支持联合实验/分析研究的实验阶段，其中分析部分由NASA支持。在实验研究中，利用梯度级显微镜设备，通过透明池进行视频成像，对琥珀腈-莰烯体系进行定向凝固。这将通过推进凝固前沿提供超细颗粒和液滴的排斥和捕获的重要信息。利用Rame-Hart垂坠装置，将测量组件界面张力。获得的数据将用于验证在NASA资助下开发的分析模型。特别是，验证将取决于预测的临界液滴尺寸与最大的液滴的测量拒绝由推进凝固前沿确定的视频成像数据。这项工作将为定向凝固中液滴的剔除提供第一个实验数据。所有先前的研究都涉及固体颗粒的去除。

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.