GTN Model-Based Material Parameters of AZ31 Magnesium Sheet at Various Temperatures by Means of SEM In-Situ Testing
GTN Model-Based Material Parameters of AZ31 Magnesium Sheet at Various Temperatures by Means of SEM In-Situ Testing
复制标题
DOI：
10.3390/cryst10100856
复制
发表时间：
2020-10-01
期刊：
影响因子：
2.7
通讯作者：
Prahl, Ulrich
中科院分区：
文献类型：
--
作者：
Henseler, Thorsten;Osovski, Shmuel;Prahl, Ulrich
镁合金主要与复杂的形成机制有关，后者在高温下产生延展性。在钣金形成中，高三轴性应力表示有利于无效形成和生长的延性损伤机制，这是可延展金属的。迄今为止，由于对AZ31镁镁的损伤参数的不完全确定，耦合损伤模型的配方迄今已失败。进行了定量研究，以确定双卷铸造，热滚动和退火的AZ31薄纸的延展性损伤行为。 Results on the mechanisms of void nucleation-, coalescence- and growth-rate were established at temperatures ranging from room temperature to 350 degrees C. In-situ tensile tests were carried out in a scanning electron microscope with three different specimen types: Simple tension specimens, notched specimens for high triaxiality stress state testing, and shear specimens.通过对通过数字图像相关性和局部空隙体积分数测量的局部菌株的比较分析，通过对标本横截面的验尸分析确定的GTN（Gurson-Tvergaard-needleman）基于模型的材料参数是通过实验确定的，代表了镁研究领域的新出发。在这种情况下开发的过程也应以薄薄的形式转移到其他金属。
Magnesium alloys are primarily associated with complex forming mechanisms, which yield ductility at high temperatures. In sheet metal forming, high triaxiality stress states that favor the ductile damage mechanisms of void formation and growth are known to malleable metals. The formulation of coupled damage models has so far failed, due to the incomplete experimental determination of damage parameters for magnesium AZ31 thin sheet. A quantitative investigation was conducted to determine the ductile damage behavior of twin-roll cast, hot rolled, and annealed AZ31 thin sheet. Results on the mechanisms of void nucleation-, coalescence- and growth-rate were established at temperatures ranging from room temperature to 350 degrees C. In-situ tensile tests were carried out in a scanning electron microscope with three different specimen types: Simple tension specimens, notched specimens for high triaxiality stress state testing, and shear specimens. Through a comparative analysis of local strains measured by digital image correlation and local void volume fractions determined through post-mortem analysis of specimen cross-sections, GTN (Gurson-Tvergaard-Needleman) model-based material parameters were determined by experiment, representing a novel departure in the magnesium research landscape. The procedure developed in this context should also be transferable to other metals in the form of thin sheets.