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Characterisation and modelling of the biaxial material behaviour of twin-roll-cast, hot rolled and annealed AZ31 sheets

双辊铸件、热轧和退火 AZ31 板材的双轴材料行为的表征和建模

基本信息

批准号：
396576920
负责人：
Professorin Dr.-Ing. Birgit Awiszus
金额：
--
依托单位：
Institut für Metallformung
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/396576920?language=en
关键词：
Characterisation modelling biaxial material behaviour

项目摘要

Mostly ecological aspects are the driving force for the development of innovative lightweight solutions nowadays. Especially the use of light metals such as magnesium is of remarkable importance. In this regard, the resource-saving and economical roll-casting of magnesium strip was developed. Due to the hexagonal lattice structure and thus reduced number of sliding systems at room temperature, the metal forming processing of roll-cast magnesium strip is difficult. Alternative deformation mechanisms as twinning, grain boundary sliding and kink banding which perform differently depending on stress-modus, temperature and deformation degree, have a decisive influence on the forming properties. It therefore requires accurate modelling and approaches to depict the realmaterial behaviour, in order to carry out a realistic technological design using numerical simulation. Standardized material models and datasets to describe anisotropy, flow locus, microstructural development and damage have reached the limits of their validity,with the consequence of inaccurate or false results in the numerical calculation. Previously developed models have been designed for continuously casted and then hot-rolled sheets of AZ31 magnesium alloy, which at present only show inadequate references to the consideration of biaxial stress states. Specifically, the biaxialcompression-compression and tension-compression stress states have been rarely studied, although this is of immense importance for modelling the flow locus. To date the deficiency of focus lies in the correlation of influencing micro-structure and coupling of the resulting mechanical properties. In this context, the consideration of inductiveheating and damage under biaxial stresses in process-relevant conditions is absent. To generate scientific added value, models regarding anisotropic material behaviour, damage and forming limit behaviour should be designed, expanded and validated for roll-cast, hot-rolled and annealed AZ31 sheet. Here, firstly uniaxial stress states will be investigated and in the subsequent phase of the project all models will be adapted to biaxial stress states and tested through a real deep drawing process with complex geometry. The result of the research project will have an increase of numerical predictioncapability and precision as outcome, in order to improve the material modelling for metal forming processes and expand the application possibilities of magnesium alloys.

大多数生态方面是当今开发创新轻量化解决方案的驱动力。特别是使用轻金属如镁是非常重要的。在此基础上，开发了资源节约型、经济型镁合金薄带铸轧技术。由于镁合金铸轧带具有六方点阵结构，因此在室温下减少了滑动系统的数量，因此金属成形加工是困难的。孪生、晶界滑移和扭折带等变形机制对成形性能有决定性的影响，这些变形机制在应力模式、温度和变形程度等方面的表现各不相同。因此，它需要精确的建模和方法来描述真实的材料行为，以便使用数值模拟进行现实的技术设计。描述各向异性、流动轨迹、微观结构发展和损伤的标准化材料模型和数据集已经达到其有效性的极限，其结果是数值计算中的不准确或错误的结果。以前开发的模型已被设计为连续铸造，然后热轧板的AZ 31镁合金，目前只显示出不充分的参考双轴应力状态的考虑。具体地说，双轴压缩-压缩和拉伸-压缩应力状态很少被研究，尽管这对于模拟流动轨迹是非常重要的。目前研究的不足之处在于影响微观结构的相关性和力学性能的耦合性。在这种情况下，在工艺相关条件下双轴应力下的感应加热和损伤的考虑是缺席的。为了产生科学的附加值，应针对铸轧、热轧和退火AZ 31板材设计、扩展和验证关于各向异性材料行为、损伤和成形极限行为的模型。在这里，首先将研究单轴应力状态，在项目的后续阶段，所有模型将适用于双轴应力状态，并通过复杂几何形状的真实的深拉工艺进行测试。研究成果将提高数值预测能力和精度，以改善金属成形过程的材料模型，扩大镁合金的应用可能性。