Creep Behavior of a 4.5% Re Nickel-Base Single Crystal Superalloy at High Temperature

Abstract:

By means of heat treatment and creep property measurement, an investigation has made into the creep behaviors of a containing 4.5% Re nickel-base single crystal superalloy at high temperature. Results show that the elements W, Mo and Re are enriched in the dendrite arm regions, the elements Al, Ta, Cr and Co are enriched in the inter-dendrite region, and the segregation extent of the elements may be obviously reduced by means of heat treatment at high temperature. In the temperature ranges of 1070--1100 °C, the 4.5% Re single crystal nickel-based superallloy displays a better creep resistance and longer creep life. The deformation mechanism of the alloy during steady state creep is dislocations slipping in the γ matrix and climbing over the rafted γ′ phase. In the later stage of creep, the deformation mechanism of alloy is dislocations slipping in the γ matrix, and shearing into the rafted γ′ phase, which may promote the initiation and propagation of the micro-cracks at the interfaces of γ/γ′ phases up to the occurrence of creep fracture.

• Periodical: Applied Mechanics and Materials (Volume 750)
• Pages: 139-144
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.750.139
• Online since: April 2015
• Authors: De Long Shu, Su Gui Tian*, Xin Ding, Jing Wu, Qiu Yang Li, Chong Liang Jiang
• Keywords: Creep Behavior, Element Re, Elements Segregation, Heat Treatment, Nickel-Base Single Crystal Superalloy

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