Effect mechanism of Ni coating layer on the characteristics of Al/steel dissimilar metal brazing
| Autor: | Jihua Huang, Shuhai Chen, Tianpeng Zou, Gaoyang Yu, Zhiyi Zhao, Jian Yang |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Filler metal Materials science Mechanical Engineering Alloy 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Coating Mechanics of Materials 0103 physical sciences Shear strength engineering Brazing General Materials Science Composite material 0210 nano-technology Dissolution Layer (electronics) |
| Zdroj: | Materials Characterization. 167:110518 |
| ISSN: | 1044-5803 |
| DOI: | 10.1016/j.matchar.2020.110518 |
| Popis: | To investigate the influence of Ni coating layer on the interfacial reaction of Al/steel dissimilar metal brazing, a high-frequency brazing method of Al alloy and steel with/without a Ni coating layer were designed. The steel side interfacial microstructure of the Al/bare steel joint consisted of Fe (Al,Si)3, Al7.2Fe1.8Si. After the preparation of the Ni coating layer on the stainless steel, the interfacial microstructure consisted of Al3Ni, Al3Ni2, and residual Ni coating layer. An ultra-thin Al3Ni2 reaction layer was observed in Al/Ni-coated steel joint by transmission electron microscopy (TEM). With increasing reaction time, the Ni coating layer completely dissolved into liquid filler metal. Interfacial structure transformed into Fe(Al,Si)3/Al7.2Fe1.8Si, which was the same as that of the Al/bare steel joint. The shear strength of the joint with the Ni-coated layer increased first and then decreased with increasing brazing time, which was influenced by the dissolution level of Ni coating layer. The maximum shear strength exceeded 20.3% that of the joint without Ni coating layer. The element diffusion phenomenon in the field of the solid/liquid interface and the dissolution behavior of the Ni coating layer were analyzed by the thermodynamics method. A model of Ni dissolution kinetics was established to optimize the thickness of the Ni coating layer and the processing parameters of the brazing. The effect mechanism of Ni coating layer on the interfacial reaction of the Al/steel dissimilar metal brazing was clarified. |
| Databáze: | OpenAIRE |
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