Process-structure-property relations for as-deposited solid-state additively manufactured high-strength aluminum alloy
Process-structure-property relations for as-deposited solid-state additively manufactured high-strength aluminum alloy
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DOI：
10.1016/j.addma.2021.101879
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发表时间：
2021-04-01
影响因子：
11
通讯作者：
Allison, P. G.
中科院分区：
文献类型：
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作者：
Mason, C. J. T.;Rodriguez, R., I;Allison, P. G.
固态增材制造方法提供了创新的解决方案，避免了材料易热裂的问题，避免了液固相转变。在这项工作中，首次量化了工艺参数对全致密铝合金7050 （AA7050）部件的微观组织演变和力学响应的影响，该部件是通过被称为添加剂搅拌摩擦沉积（AFS-D）的快速固态增材制造工艺制造的。对表现出不同热机械加工历史的沉积的三个部分（起始停留，瞬态，交叉道路）进行了评估，以获得微观结构和机械响应。通过电子背散射衍射（EBSD）、透射电子显微镜（TEM）、光学显微镜和扫描电子显微镜（SEM）对沉积的AA7050进行了微观结构表征。显微组织表征表明，沉积态AA7050的显微组织中存在细化的组成颗粒和晶粒。此外，为了量化取向对沉积态AA7050 build拉伸性能的影响，我们在build和横向进行了准静态拉伸实验。由于热输入的变化，二次相向AFS-D构建的初始层粗化，在材料中观察到空间依赖的拉伸性能。事后分析显示，由于材料中存在的强化相过度生长，导致空洞成核并合并，从而导致断裂。
Solid-state additive manufacturing methods provide innovative solutions to circumvent problems associated with materials susceptible to hot cracking by avoiding liquid solid phase transformations. In this work, the process parameter influence on microstructural evolution and mechanical response of a fully dense aluminum alloy 7050 (AA7050) component manufactured via a rapid, solid-state additive manufacturing process known as Additive Friction Stir Deposition (AFS-D) was quantified for the first time. Three sections (starting dwell, transient, crossover of roads) of the deposition that exhibit differing thermomechanical processing histories were evaluated for the resulting microstructure and mechanical response. The microstructural characterization was performed on the as-deposited AA7050 via Electron Backscatter Diffraction (EBSD), Transmission electron microscopy (TEM), optical microscopy, and Scanning Electron Microscopy (SEM). The microstructural characterization revealed refined constituent particles and grains throughout the as-deposited AA7050 microstructure. Furthermore, quasi-static tensile experiments were conducted in both the build and transverse directions, in order to quantify the orientation influence on tensile properties of the as-deposited AA7050 build. Spatially dependent tensile properties were observed in the material due to heat input variation coarsening of secondary phases towards the initial layers of the AFS-D build. Post-mortem analysis revealed that voids nucleated and coalesced from the overgrowth of the strengthening precipitates present in the material, resulting in fracture.