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.

如今，主要是生态方面的驱动力。特别是使用镁等光金属的使用非常重要。在这方面，开发了镁带的资源储蓄和经济滚动量。由于六角形晶格结构，因此在室温下减少了滑动系统的数量，因此很难在室温下形成金属形成镁条的加工。替代变形机制作为孪生，晶界滑动和扭结频带，根据应力 - 模型，温度和变形程度的性能有所不同，对形成特性具有决定性的影响。因此，它需要精确的建模和描述现场行为的方法，以便使用数值模拟进行现实的技术设计。标准化的材料模型和数据集描述各向异性，流量基因座，微观结构发展和损害已达到其有效性的限制，这导致数值计算导致不准确或错误的结果。先前开发的模型是针对AZ31镁合金的连续铸造和热卷的设计的，目前仅显示对双轴应力状态的考虑不足。具体而言，尽管这对于对流动基因座进行建模至关重要，但很少研究双轴压缩压缩和张力压缩应力状态。迄今为止，重点的不足在于影响微结构和所得机械性能的耦合的相关性。在这种情况下，不考虑对相关条件下双轴应力下的感应护理和损害的考虑。为了产生科学的增加价值，应设计，扩展和验证有关各向异性物质行为，损害和形成极限行为的模型，以进行滚动，热卷和退火的AZ31纸。在这里，首先将研究单轴应力状态，并在项目的随后阶段进行所有模型，所有模型都将适应双轴应力状态，并通过具有复杂几何形状的真实深度绘图过程进行了测试。研究项目的结果将增加数值的预测能力和精度为结果，以改善金属形成过程的材料建模并扩大镁合金的应用可能性。