{"title":"Relationship between characteristics of liquid film and hot tearing phenomena during solidification of hypereutectic Al-Si alloy","authors":"Rui Zhou, Xiaogang Fang, Kaixuan Zhang, Junchao Yu, Chao Gao, Yiqing Chen","doi":"10.1007/s10853-025-10863-0","DOIUrl":null,"url":null,"abstract":"<div><p>The alloy in the final stage of solidification is in the semi-solid region, composed of solid grains and liquid film. This article focuses on the effect of liquid film on hot tearing in the final stage of solidification. It investigates the mechanism of the effect of liquid film on the initiation of hot tearing. The mechanical behavior of Al-27%Si hypereutectic Al-Si alloy in high-temperature stress–strain testing was studied. The results showed that the overall content of the liquid film during the solidification process affects the mechanical properties of the alloy; the alloy exhibited viscoelasticity in a high solid fraction state and viscoplasticity in a low solid fraction state. At the same time, a Si-liquid film-Si structure was constructed to simulate the intergranular liquid film structure of hypereutectic Al-Si alloy in the final stage of solidification. The stress variation characteristics of the intergranular liquid film showed that the smaller the liquid film thickness, the stronger the interaction force between Si wafers, which is not conducive to improving the liquid film fluidity. In addition, the fracture morphology of the tensile fracture was observed, and it was found that under the condition of thick liquid film, the flowability of the residual liquid phase was better, making it easier to feed for hot tearing. Finally, CFD simulation technology was used to study the mechanism of the effect of a single factor of liquid film characteristics on hot tearing. The results showed that the thicker the liquid film, the greater its ability to feed and heal the formed hot tearing, thus effectively reducing the alloy's tendency toward hot tearing.</p></div>","PeriodicalId":645,"journal":{"name":"Journal of Materials Science","volume":"60 16","pages":"6987 - 7001"},"PeriodicalIF":3.5000,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Materials Science","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s10853-025-10863-0","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The alloy in the final stage of solidification is in the semi-solid region, composed of solid grains and liquid film. This article focuses on the effect of liquid film on hot tearing in the final stage of solidification. It investigates the mechanism of the effect of liquid film on the initiation of hot tearing. The mechanical behavior of Al-27%Si hypereutectic Al-Si alloy in high-temperature stress–strain testing was studied. The results showed that the overall content of the liquid film during the solidification process affects the mechanical properties of the alloy; the alloy exhibited viscoelasticity in a high solid fraction state and viscoplasticity in a low solid fraction state. At the same time, a Si-liquid film-Si structure was constructed to simulate the intergranular liquid film structure of hypereutectic Al-Si alloy in the final stage of solidification. The stress variation characteristics of the intergranular liquid film showed that the smaller the liquid film thickness, the stronger the interaction force between Si wafers, which is not conducive to improving the liquid film fluidity. In addition, the fracture morphology of the tensile fracture was observed, and it was found that under the condition of thick liquid film, the flowability of the residual liquid phase was better, making it easier to feed for hot tearing. Finally, CFD simulation technology was used to study the mechanism of the effect of a single factor of liquid film characteristics on hot tearing. The results showed that the thicker the liquid film, the greater its ability to feed and heal the formed hot tearing, thus effectively reducing the alloy's tendency toward hot tearing.
期刊介绍:
The Journal of Materials Science publishes reviews, full-length papers, and short Communications recording original research results on, or techniques for studying the relationship between structure, properties, and uses of materials. The subjects are seen from international and interdisciplinary perspectives covering areas including metals, ceramics, glasses, polymers, electrical materials, composite materials, fibers, nanostructured materials, nanocomposites, and biological and biomedical materials. The Journal of Materials Science is now firmly established as the leading source of primary communication for scientists investigating the structure and properties of all engineering materials.