Guo Chenhao, Yu Jinjiang, Liu Jinlai, Sun Xiaofeng, Zhou Yizhou
Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China.
Materials (Basel). 2021 Apr 27;14(9):2250. doi: 10.3390/ma14092250.
DZ951G is a novel developed nickel-based directional solidified superalloy with an incipient high melting point and low density. Compared with DZ417G superalloy, DZ951G superalloy has a higher ultimate tensile strength. At intermediate temperatures, the plasticity and strength were both markedly improved, and an obviously anomalous yield behavior could be observed where the yield strength reached its maximum at 760 °C. Below 600 °C, two competitive modes of dislocations shearing γ' particles existed, in which one was the formation of stacking faults and another was a/2<101> dislocations shearing. At intermediate temperatures, a transitional phase between shearing γ' particles and bypassing appeared, and the fracture translated from brittle fracture into ductile fracture. Exceeding 900 °C, bypassing of dislocations was operated under thermal activation. Moreover, short continuous stacking faults still existed at 760 °C. Finally, the various dislocation configurations were rationally illuminated and explained with the intrinsic connection of mechanical properties.
DZ951G是一种新研制的镍基定向凝固高温合金，具有初熔点高、密度低的特点。与DZ417G高温合金相比，DZ951G高温合金具有更高的抗拉强度。在中温下，其塑性和强度均显著提高，且在760℃时屈服强度达到最大值，呈现出明显的异常屈服行为。在600℃以下，存在两种位错剪切γ'相粒子的竞争模式，一种是形成层错，另一种是a/2<101>位错剪切。在中温下，出现了位错剪切γ'相粒子和绕过γ'相粒子的过渡阶段，断裂方式从脆性断裂转变为韧性断裂。超过900℃时，位错绕过在热激活作用下进行。此外，在760℃时仍存在短程连续层错。最后，利用力学性能的内在联系，对位错的各种组态进行了合理的阐释。
