Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage Tendency
Shrinkage greatly influences the mechanical and fatigue properties of compacted graphite iron and it is necessary in order to study the causes of shrinkage in compacted graphite iron and to predict it effectively. In this paper, a kind of cylindrical necking test sample was designed to evaluate the...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-11-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/15/23/8413 |
| _version_ | 1797462897200201728 |
|---|---|
| author | Zeyu Liu Dequan Shi Guili Gao Yicheng Feng |
| author_facet | Zeyu Liu Dequan Shi Guili Gao Yicheng Feng |
| author_sort | Zeyu Liu |
| collection | DOAJ |
| description | Shrinkage greatly influences the mechanical and fatigue properties of compacted graphite iron and it is necessary in order to study the causes of shrinkage in compacted graphite iron and to predict it effectively. In this paper, a kind of cylindrical necking test sample was designed to evaluate the shrinkage in compacted graphite iron, and a method to calculate the size of shrinkage was proposed. By observing the microstructure around the shrinkage zone, it is concluded that concentrated shrinkage mainly appears in the solidification region where the dendritic gap is closed, and the isolated shrinkage mainly occurs in the final solidification region, and the supersaturated carbon elements are gathered on the surface of the shrinkage. The cause of shrinkage in compacted graphite iron is caused by its solidification method, where the austenite dendrites and the eutectic clusters are generated close to the melt zone during the solidification process, leading to the inability to feed the shrinkage. Based on the thermodynamic analysis, the equations between the volume change of each phase, solid phase rate, and time during solidification of compacted graphite iron were established to theoretically explain the formation mechanism of the shrinkage. Taking nine parameters such as the chemical elements and characteristic values of thermal analysis as the input nods, a four-layer BP neural network model for predicting the size of shrinkage in compacted graphite iron was constructed, and the R-squared of the model reached 97%, which indicates it could be used to predict the shrinkage tendency. |
| first_indexed | 2024-03-09T17:43:02Z |
| format | Article |
| id | doaj.art-deeeecc83b27450bbc093d942d3cb5e1 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T17:43:02Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-deeeecc83b27450bbc093d942d3cb5e12023-11-24T11:27:48ZengMDPI AGMaterials1996-19442022-11-011523841310.3390/ma15238413Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage TendencyZeyu Liu0Dequan Shi1Guili Gao2Yicheng Feng3School of Materials Science and Chemical Engineering, Harbin University of Science and Technology, Harbin 150040, ChinaSchool of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, ChinaSchool of Mechanical and Energy Engineering, Shanghai Technical Institute of Electronics and Information, Shanghai 201411, ChinaSchool of Materials Science and Chemical Engineering, Harbin University of Science and Technology, Harbin 150040, ChinaShrinkage greatly influences the mechanical and fatigue properties of compacted graphite iron and it is necessary in order to study the causes of shrinkage in compacted graphite iron and to predict it effectively. In this paper, a kind of cylindrical necking test sample was designed to evaluate the shrinkage in compacted graphite iron, and a method to calculate the size of shrinkage was proposed. By observing the microstructure around the shrinkage zone, it is concluded that concentrated shrinkage mainly appears in the solidification region where the dendritic gap is closed, and the isolated shrinkage mainly occurs in the final solidification region, and the supersaturated carbon elements are gathered on the surface of the shrinkage. The cause of shrinkage in compacted graphite iron is caused by its solidification method, where the austenite dendrites and the eutectic clusters are generated close to the melt zone during the solidification process, leading to the inability to feed the shrinkage. Based on the thermodynamic analysis, the equations between the volume change of each phase, solid phase rate, and time during solidification of compacted graphite iron were established to theoretically explain the formation mechanism of the shrinkage. Taking nine parameters such as the chemical elements and characteristic values of thermal analysis as the input nods, a four-layer BP neural network model for predicting the size of shrinkage in compacted graphite iron was constructed, and the R-squared of the model reached 97%, which indicates it could be used to predict the shrinkage tendency.https://www.mdpi.com/1996-1944/15/23/8413compacted graphite ironshrinkagemechanism analysisthermal analysisartificial neural network |
| spellingShingle | Zeyu Liu Dequan Shi Guili Gao Yicheng Feng Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage Tendency Materials compacted graphite iron shrinkage mechanism analysis thermal analysis artificial neural network |
| title | Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage Tendency |
| title_full | Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage Tendency |
| title_fullStr | Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage Tendency |
| title_full_unstemmed | Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage Tendency |
| title_short | Mechanism of Shrinkage in Compacted Graphite Iron and Prediction of Shrinkage Tendency |
| title_sort | mechanism of shrinkage in compacted graphite iron and prediction of shrinkage tendency |
| topic | compacted graphite iron shrinkage mechanism analysis thermal analysis artificial neural network |
| url | https://www.mdpi.com/1996-1944/15/23/8413 |
| work_keys_str_mv | AT zeyuliu mechanismofshrinkageincompactedgraphiteironandpredictionofshrinkagetendency AT dequanshi mechanismofshrinkageincompactedgraphiteironandpredictionofshrinkagetendency AT guiligao mechanismofshrinkageincompactedgraphiteironandpredictionofshrinkagetendency AT yichengfeng mechanismofshrinkageincompactedgraphiteironandpredictionofshrinkagetendency |