Tailored Heat Treated Profiles - Enhancement of the Forming Limit of Aluminum Profiles under Bending Load
Tailored Heat Treated Profiles - Enhancement of the Forming Limit of Aluminum Profiles under Bending Load
复制标题
定制热处理型材 - 提高铝型材在弯曲载荷下的成形极限
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
R. Plettke
中科院分区：
文献类型：
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作者：
M. Merklein;M. Lechner;T. Schneider;R. Plettke
铝型材是轻质结构中成熟的部件。然而，与钢型材相比，这些型材的成型能力较小，这导致其应用受到限制。本文提出了一种新的创新方法，用于提高铝型材在弯曲载荷下的成形极限，称为定制热处理型材 (THTP)。通过 THTP，材料的机械性能可通过短期热处理进行局部修改。通过这种局部修改，可以影响随后的冷弯操作期间的材料流动。对于热处理布局的设计，必须研究热处理参数与材料性能之间的相关性。从型材上切下拉伸样品，然后用激光进行完全热处理。通过拉伸试验分析了热处理引起的力学性能的变化。然而，随着型材的完全软化，成形性无法得到改善。为了提高成形性，必须研究导致型材部分软化的局部热处理。为了表征激光处理的热影响区 (HAZ)，进行了热像仪和显微硬度测量。必须找到适当的热处理布局来提高成形极限。开发了不同的布局策略，然后通过热处理和型材成型进行验证。本文将介绍本次调查的结果，并表明 THTP 可用于提高弯曲操作铝型材的成型性。
Aluminum profiles are well-established components in lightweight constructions. However, these profiles have a small forming capability in comparison to steel profiles, which leads to a limitation in their application. Within this paper a new and innovative approach for the enhancement of the forming limit of aluminum profiles under bending load called Tailored Heat Treated Profiles (THTP) is presented. With THTP the mechanical properties of the material are locally modified by a short-term heat treatment. By this local modification the material flow during the following cold bending operation can be influenced. For the design of the heat treatment layout, the correlation between the heat treatment parameters and the material properties has to be investigated. Tensile specimens were cut out of the profile and were subsequently completely heat treated with a laser. The changes of the mechanical properties caused by the heat treatment were analyzed by tensile tests. However, with a complete softening of the profile, the formability could not be improved. To increase the formability a local heat treatment, which leads to partial softening of the profile, has to be investigated. In order to characterize the heat-affected zone (HAZ) of the laser treatment, thermal camera and microhardness measurements were carried out. Appropriate heat treatment layouts have to be found to enhance the forming limit. Different layout strategies were developed and afterwards validated by the heat treatment and forming of profiles. This paper will present the findings of this investigation and show that THTP can be used to improve the formability of aluminum profiles for bending operations.