Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study
The columnar-to-equiaxed transition (CET) is commonly observed in laser welds. It is able to prevent the growth of large columnar grains and consequently improve the mechanical properties of welded joints. In this paper, the CET behaviors at different locations in the laser weld of an Al–Mg alloy ar...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-03-01
|
| Series: | Metals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4701/12/4/571 |
| _version_ | 1797434384023814144 |
|---|---|
| author | Lingyu Guo Chu Han Liangyuan Ren Wen Yang Annan Yin |
| author_facet | Lingyu Guo Chu Han Liangyuan Ren Wen Yang Annan Yin |
| author_sort | Lingyu Guo |
| collection | DOAJ |
| description | The columnar-to-equiaxed transition (CET) is commonly observed in laser welds. It is able to prevent the growth of large columnar grains and consequently improve the mechanical properties of welded joints. In this paper, the CET behaviors at different locations in the laser weld of an Al–Mg alloy are observed experimentally and studied systematically. In order to describe the dynamic CET behaviors, an integrated phase-field (PF) model coupled with transient thermal conditions and a Gaussian heterogeneous nucleation model is developed. Investigations on columnar growth under steady conditions are performed first. In particular, the effects of thermal conditions, i.e., solidification rate and temperature gradient, on the constitutionally undercooled degree and region ahead of the solidification front are quantitatively studied. In a laser weld, it is found that the CET behaviors vary significantly along the thickness direction. Our PF simulation results indicate that the CET depends strongly on the locally transient thermal conditions in the fusion zone. The transient thermal conditions affect CET behaviors by dynamically adjusting the constitutionally undercooled degree and region during the solidification process. The predicted CET behaviors under transient conditions exhibit reasonably good agreements with corresponding experimental results. |
| first_indexed | 2024-03-09T10:32:22Z |
| format | Article |
| id | doaj.art-ba4f01900cfc446f801e804eb002ac13 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-09T10:32:22Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-ba4f01900cfc446f801e804eb002ac132023-12-01T21:13:46ZengMDPI AGMetals2075-47012022-03-0112457110.3390/met12040571Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field StudyLingyu Guo0Chu Han1Liangyuan Ren2Wen Yang3Annan Yin4The State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, ChinaThe State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, ChinaThe State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, ChinaThe State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, ChinaThe State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science & Technology, Wuhan 430074, ChinaThe columnar-to-equiaxed transition (CET) is commonly observed in laser welds. It is able to prevent the growth of large columnar grains and consequently improve the mechanical properties of welded joints. In this paper, the CET behaviors at different locations in the laser weld of an Al–Mg alloy are observed experimentally and studied systematically. In order to describe the dynamic CET behaviors, an integrated phase-field (PF) model coupled with transient thermal conditions and a Gaussian heterogeneous nucleation model is developed. Investigations on columnar growth under steady conditions are performed first. In particular, the effects of thermal conditions, i.e., solidification rate and temperature gradient, on the constitutionally undercooled degree and region ahead of the solidification front are quantitatively studied. In a laser weld, it is found that the CET behaviors vary significantly along the thickness direction. Our PF simulation results indicate that the CET depends strongly on the locally transient thermal conditions in the fusion zone. The transient thermal conditions affect CET behaviors by dynamically adjusting the constitutionally undercooled degree and region during the solidification process. The predicted CET behaviors under transient conditions exhibit reasonably good agreements with corresponding experimental results.https://www.mdpi.com/2075-4701/12/4/571columnar-to-equiaxed transitionlaser weldingtransient thermal conditionphase-field model |
| spellingShingle | Lingyu Guo Chu Han Liangyuan Ren Wen Yang Annan Yin Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study Metals columnar-to-equiaxed transition laser welding transient thermal condition phase-field model |
| title | Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study |
| title_full | Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study |
| title_fullStr | Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study |
| title_full_unstemmed | Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study |
| title_short | Effect of Transient Thermal Conditions on Columnar-to-Equiaxed Transition during Laser Welding: A Phase-Field Study |
| title_sort | effect of transient thermal conditions on columnar to equiaxed transition during laser welding a phase field study |
| topic | columnar-to-equiaxed transition laser welding transient thermal condition phase-field model |
| url | https://www.mdpi.com/2075-4701/12/4/571 |
| work_keys_str_mv | AT lingyuguo effectoftransientthermalconditionsoncolumnartoequiaxedtransitionduringlaserweldingaphasefieldstudy AT chuhan effectoftransientthermalconditionsoncolumnartoequiaxedtransitionduringlaserweldingaphasefieldstudy AT liangyuanren effectoftransientthermalconditionsoncolumnartoequiaxedtransitionduringlaserweldingaphasefieldstudy AT wenyang effectoftransientthermalconditionsoncolumnartoequiaxedtransitionduringlaserweldingaphasefieldstudy AT annanyin effectoftransientthermalconditionsoncolumnartoequiaxedtransitionduringlaserweldingaphasefieldstudy |