Influence of Cooling Holes Distribution on Stress Rupture Property and Fracture Behavior of Single Crystal Superalloy DD6
HU Chun-yan1,2, LIU Xin-ling1,2, TAO Chun-hu1,2, CAO Chun-xiao1,2
1. Beijing Institute of Aeronautical Materials, Beijing 100095, China;
2. Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation, Beijing 100095, China
Abstract:The influence of different cooling holes distribution on stress rupture property and fracture behavior of air-cooled turbine blades modeling specimens of single crystal superalloy DD6 at 980℃/300MPa was analyzed. The results show that cooling holes distribution is the main factor affecting the stress rupture life at the same temperature and stress conditions. The stress rupture life of modeling specimens declines regularly as rows of cooling holes increase, however, the stress rupture life of modeling specimens with one row cooling holes or two rows cooling holes is slightly longer than that without cooling holes. Based on fracture surface and metallurgical observations, the specimens without cooling holes fracture in the mode of microvoid coalescence. The fracture surface is made up of small square-shaped facets and there are heart checks near the fracture surfaces of the specimens,but for the specimens with cooling holes, the fracture cracks initiate from the cooling holes and stress rupture deformation concentrates on the region near cooling holes. The whole fracture surface oxidizes seriously and the small square-shaped facets reduce, dimples increase. In addition, there are cracks and oxidization characteristics near the fracture surfaces of the specimens. Based on the crystal plasticity theory, the distribution of stress along cooling holes is obtained. The simulated results show that stress concentration and redistribution occur around the cooling holes, and the form of the fracture surface is consistent with numerical analysis.
胡春燕, 刘新灵, 陶春虎, 曹春晓. 气膜孔分布对DD6单晶高温合金持久性能及断裂行为的影响[J]. 材料工程, 2016, 44(5): 93-100.
HU Chun-yan, LIU Xin-ling, TAO Chun-hu, CAO Chun-xiao. Influence of Cooling Holes Distribution on Stress Rupture Property and Fracture Behavior of Single Crystal Superalloy DD6. Journal of Materials Engineering, 2016, 44(5): 93-100.
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