Crystal Plasticity Mechanism of Temperature-Dependent Crack Propagation in a Single Crystal Nickel-Based Superalloy
Crystal Plasticity Mechanism of Temperature-Dependent Crack Propagation in a Single Crystal Nickel-Based Superalloy
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DOI：
10.1007/978-3-030-51834-9_31
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Xiaosheng Chen;M. Sakaguchi;S. Suzuki;H. Inoue;M. Okazaki
中科院分区：
文献类型：
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作者：
Xiaosheng Chen;M. Sakaguchi;S. Suzuki;H. Inoue;M. Okazaki
对一种镍基单晶高温合金的温度相关疲劳裂纹扩展进行了实验和数值研究。在室温300、450和700 °C下，使用四种类型的紧凑试样进行疲劳裂纹扩展试验，这些试样在加载和裂纹扩展方向上具有不同的晶体取向组合。实验结果表明，室温下裂纹以晶体开裂方式沿沿着面扩展，而在300、450和700°C下裂纹由I型向晶体开裂转变。转变时的I型应力强度因子范围Δ KI值取决于测试温度和晶体取向。为了解释这些温度相关的裂纹扩展，晶体塑性有限元分析进行了考虑到三维倾斜裂纹面和裂纹前的滑移面的活动。滑移面活动，提出作为一个损伤参数，可以合理的疲劳裂纹扩展速率在晶体学和模式I开裂。结果表明，晶体裂纹的裂纹扩展阻力在低温下基本相同，而I型裂纹的裂纹扩展阻力随温度的升高而减小。这个损伤参数也提供了一个解释的临界条件，诱导从模式I的晶体开裂的过渡。
Temperature-dependent fatigue crack propagation in a Ni-based single crystal superalloy was experimentally and numerically investigated in a single crystal Ni-based superalloy. Fatigue crack propagation tests at room temperature 300, 450, and 700 °C were conducted using four types of compact specimens with different combinations of crystal orientations in loading and crack propagation directions. It was revealed in the experiments that the crack propagated along slip planes in crystallographic cracking manner at room temperature, while the cracking mode transitioned from the Mode I to crystallographic cracking at 300, 450, and 700°C. Mode I stress intensity factor range ΔKIvalues at the transitions depended on the testing temperature as well as crystal orientation. To interpret these temperature-dependent crack propagation, a crystal plasticity finite element analysis was conducted by taking into account the 3D inclined crack plane and the activity of slip planes in front of the crack. Slip plane activity, proposed as a damage parameter, could rationalize the fatigue crack propagation rates both during the crystallographic and Mode I cracking. It has been found that crack propagation resistance for crystallographic cracking is more or less the same at low temperature, while that for Mode I cracking decreases with the increase of the temperature. This damage parameter also provided an explanation of the critical condition that induces the transition from Mode I to crystallographic cracking.