Thermal Analysis and Production of As-Cast Al 7075/6060 Bilayer Billets
Thermal Analysis and Production of As-Cast Al 7075/6060 Bilayer Billets
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DOI：
10.1007/s40962-018-0282-8
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发表时间：
2018-12
影响因子：
2.6
通讯作者：
T. Greß;T. Mittler;S. Schmid;Hui Chen;N. Ben Khalifa;W. Volk
中科院分区：
文献类型：
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作者：
T. Greß;T. Mittler;S. Schmid;Hui Chen;N. Ben Khalifa;W. Volk
负载调整，重量优化组件可以通过以下多材料方法制造。将Al 7075和Al 6060各自的强度和耐腐蚀性优势整合到一个单一的结构部件中导致复杂的性能轮廓。复合铸造在工艺链缩短、材料效率和粘合质量方面具有很高的潜力。介绍了采用多步不连续复合铸造工艺生产铝双层方坯的方法。研究了影响界面内聚键形成的工艺条件。为了充分表征铸造合金，进行了基本的热分析。采用工艺参数和热物理数据相结合的方法可以确定Al 7075和Al 6060的冶金结合工艺窗口。发现基体合金的主要结合机制是外延凝固，外延凝固是通过基体合金的重熔和再结晶发生的。在这里，枝晶相干点构成了形成固溶体的近界面衬底温度的临界水平。利用SEM-EDS分析了外延、相组成和金属间扩散过程。
Load-adjusted, weight-optimized components can be fabricated by following a multi-material approach. Integrating the respective advantages of strength and corrosion resistance of Al 7075 and Al 6060 into a single structural component leads to a complex property profile. Compound casting offers a high potential in terms of process chain shortening, material efficiency and bonding quality. The present paper focuses on the production of aluminum bilayer billets by multi-step, discontinuous compound casting. Process conditions influencing the formation of a cohesive bond at the interface are investigated. A fundamental thermal analysis is conducted in order to fully characterize the casting alloys. A process window for metallurgical bonding of Al 7075 and Al 6060 can be defined using a combined approach of process parameters and thermophysical data. The primary bonding mechanism is found to be the epitaxial solidification which occurs through remelting and recrystallization of the substrate alloy. Here the dendrite coherence point constitutes a critical level of the near-interface substrate temperature in terms of forming a solid solution. Epitaxy, phase composition and intermetallic diffusion processes are analyzed using SEM–EDS.