Article ID Journal Published Year Pages File Type
5013478 Engineering Failure Analysis 2017 8 Pages PDF
Abstract
The specimen material is GH3536, a kind of Cr and Mo solid solution strengthened with high iron content of nickel-based superalloy, and the film cooling holes were fabricated by forming EDM and high-speed EDM. Comparative analysis of the differences between fatigue life and microscopic fracture morphology were conducted due to the different drilling processes. It is shown that under the same test condition, the average fatigue life of forming EDM specimens and high-speed EDM specimens reach 27 h and 20 h respectively. In other words, the former has better anti-fatigue property. Scanning electron microscope (SEM) analysis of the fracture revealed that the crack initiated from the film cooling holes and all of the fractures were oxidized seriously. However, more crack sources and tiny processing cracks were found in high speed EDM drilling specimens than in the forming EDM ones. Finite element analysis indicates that the existence of film cooling holes causes significant stress concentration.
Related Topics
Physical Sciences and Engineering Engineering Industrial and Manufacturing Engineering
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