Improvement of room temperature fracture toughness in Cr2Nb-based alloys by heat treatment |
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| Authors: | K. W. Li S. M. Li X. B. Wang H. Zhong Y. L. Xue H. Z. Fu |
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| Affiliation: | 1. State Key Laboratory of Solidification ProcessingNorthwestern Polytechnical University, Xi’an 710072, China;2. College of Materials Science and EngineeringTaiyuan University of Technology, Taiyuan 030024, China;3. College of Materials Science and EngineeringTaiyuan University of Technology, Taiyuan 030024, China |
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| Abstract: | The microstructure and room temperature fracture toughness of binary Cr/Cr2Nb alloys annealed at 1653 K for 30 h were investigated at both the hypo- and hypereutectic compositions. The experimental results indicate that the high temperature heat treatment has a beneficial effect on the room temperature fracture toughness of the Cr2Nb/Cr alloys. After the heat treatment, the room temperature fracture toughness of the hypo- and hypereutectic alloys are increased by about 212 and 203%, which are 15 and 8 times higher than that of as-cast Cr2Nb Laves phase (1·2 MPa m1/2). The fractographic analysis indicates that in the annealed condition, the strengthen of lamellar eutectic cohesive strength can provide significant toughening of the matrix by crack deflection, crack blunting and crack bridging mechanisms. |
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| Keywords: | Laves phase Heat treatment Fracture toughness |
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