The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample Mass
The effects of Si content (X = 4 to 7 wt.%), heating rate (5 to 25 °C/min) and sample mass (20 to 200 mg) on determination of the thixoforming working window by differential scanning calorimetry DSC were analyzed for the Al-Xwt.%Si-4wt.%Zn, or simply Al<sub>X</sub>Si<sub>4</sub&...
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MDPI AG
2022-04-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/12/5/734 |
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| author | Daimer Velazquez Tamayo Gabriela Lujan Brollo Juliana Rodrigues de Oliveira Fabio Miani Eugênio José Zoqui |
| author_facet | Daimer Velazquez Tamayo Gabriela Lujan Brollo Juliana Rodrigues de Oliveira Fabio Miani Eugênio José Zoqui |
| author_sort | Daimer Velazquez Tamayo |
| collection | DOAJ |
| description | The effects of Si content (X = 4 to 7 wt.%), heating rate (5 to 25 °C/min) and sample mass (20 to 200 mg) on determination of the thixoforming working window by differential scanning calorimetry DSC were analyzed for the Al-Xwt.%Si-4wt.%Zn, or simply Al<sub>X</sub>Si<sub>4</sub>Zn, system. The critical lower and upper temperatures for thixoforming processing were determined by applying the differentiation method to DSC heating cycle data. Lower Si content, heating rate and DSC sample mass made identification of the working window temperatures more accurate because of the sharpening of the DSC curve when lower values of these variables were used. Data obtained when lower sample masses and heating rates were used agreed better with those obtained by Calculation of Phase Diagrams, (CALPHAD) simulation (near-equilibrium Scheil condition) for all the Si contents analyzed. Larger DSC sample masses were associated with significant heterogeneity in heat transfer through the sample, leading to results similar to those for a diffuse transition, an effect enhanced by an increase in the heating rate. Since Si content represented a limitation when identifying the working window by the differentiation method, alloys with high Si content should be analyzed with lower DSC masses and lower heating rates to allow more accurate determination of the interval at conditions near those used in thixoforming operations. |
| first_indexed | 2024-03-10T03:25:59Z |
| format | Article |
| id | doaj.art-5d5676980dc540ab9e7043c0ec454b4e |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T03:25:59Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-5d5676980dc540ab9e7043c0ec454b4e2023-11-23T12:08:34ZengMDPI AGMetals2075-47012022-04-0112573410.3390/met12050734The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample MassDaimer Velazquez Tamayo0Gabriela Lujan Brollo1Juliana Rodrigues de Oliveira2Fabio Miani3Eugênio José Zoqui4Faculty of Mechanical Engineering, University de Oriente (UO), 25VM+C34, Santiago de Cuba 90500, CubaMaterials and Manufacturing Department, Faculty of Mechanical Engineering, University of Campinas, UNICAMP, Campinas 13083-860, SP, BrazilMaterials and Manufacturing Department, Faculty of Mechanical Engineering, University of Campinas, UNICAMP, Campinas 13083-860, SP, BrazilPolytechnic Department of Engineering and Architecture, University of Udine, Via delle Scienze 208, 33100 Udine, ItalyMaterials and Manufacturing Department, Faculty of Mechanical Engineering, University of Campinas, UNICAMP, Campinas 13083-860, SP, BrazilThe effects of Si content (X = 4 to 7 wt.%), heating rate (5 to 25 °C/min) and sample mass (20 to 200 mg) on determination of the thixoforming working window by differential scanning calorimetry DSC were analyzed for the Al-Xwt.%Si-4wt.%Zn, or simply Al<sub>X</sub>Si<sub>4</sub>Zn, system. The critical lower and upper temperatures for thixoforming processing were determined by applying the differentiation method to DSC heating cycle data. Lower Si content, heating rate and DSC sample mass made identification of the working window temperatures more accurate because of the sharpening of the DSC curve when lower values of these variables were used. Data obtained when lower sample masses and heating rates were used agreed better with those obtained by Calculation of Phase Diagrams, (CALPHAD) simulation (near-equilibrium Scheil condition) for all the Si contents analyzed. Larger DSC sample masses were associated with significant heterogeneity in heat transfer through the sample, leading to results similar to those for a diffuse transition, an effect enhanced by an increase in the heating rate. Since Si content represented a limitation when identifying the working window by the differentiation method, alloys with high Si content should be analyzed with lower DSC masses and lower heating rates to allow more accurate determination of the interval at conditions near those used in thixoforming operations.https://www.mdpi.com/2075-4701/12/5/734CALPHADthixoforming working windowDSCAl-Si-Zn alloys |
| spellingShingle | Daimer Velazquez Tamayo Gabriela Lujan Brollo Juliana Rodrigues de Oliveira Fabio Miani Eugênio José Zoqui The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample Mass Metals CALPHAD thixoforming working window DSC Al-Si-Zn alloys |
| title | The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample Mass |
| title_full | The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample Mass |
| title_fullStr | The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample Mass |
| title_full_unstemmed | The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample Mass |
| title_short | The Thixoforming Process Window for Al-Si-Zn Alloys Using the Differentiation Method: The Role of Si, Heating Rate and Sample Mass |
| title_sort | thixoforming process window for al si zn alloys using the differentiation method the role of si heating rate and sample mass |
| topic | CALPHAD thixoforming working window DSC Al-Si-Zn alloys |
| url | https://www.mdpi.com/2075-4701/12/5/734 |
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