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在高温状态下,镍基单晶超合金的变形、损伤及断裂分析中,孔洞的长大都起着主要的作用。本研究进行了系列的蠕变、疲劳及热机械疲劳(TMF)试验。对试件的断面进行的 SEM 观察表明,所有的断面都是有许多小断面构成,在断面的中心,至少有一个孔洞。孔洞的尺寸与加载的条件相关。使用晶体塑性有限元程序对单胞模型进行分析,模拟孔洞的长大规律。给出了蠕变和弹塑性两种条件下的模拟结果及不同的晶体取向对孔穴长大的影响结果。对孔洞长大的有限元分析有助于对实验结果的理解。
At high temperature, deformation, damage and fracture analysis of Ni-based single crystal superalloys all play a major role in the growth of pores. This study conducted a series of creep, fatigue and thermo-mechanical fatigue (TMF) tests. SEM observations of the cross section of the specimen show that all the sections have many small sections with at least one hole in the center of the section. The size of the hole is related to the loading conditions. The unit cell model was analyzed using the crystal plastic finite element program to simulate the growth law of the holes. The simulation results under different creep and elasto-plastic conditions and the effect of different crystal orientations on the cavity growth are given. Finite element analysis of hole growth helps to understand the experimental results.