Exceptional ultra-high temperature creep resistance of a [111]- oriented single crystal superalloy

Abstract

There exists a gap in current academic knowledge regarding whether [111]-oriented single crystal (SX) superalloys maintain performance advantages related to anisotropy at ultra-high temperatures (UHT), defined as 1150 °C and above. To address the UHT anisotropy, a finely-designed [111]-oriented SX superalloy, enriched with 1.5 wt.% Re, has been developed. The present alloy demonstrated an impressive creep life exceeding 200 h under conditions of 1150 °C/137 MPa, setting a record in the existing literature. This remarkable property can be attributed to the effective utilization of conventional strengthening mechanisms, as evidenced by the interaction between phases and dislocations. Additionally, the advantageous anisotropy associated with the [111] orientation offers a solution to the trade-off between UHT creep resistance and material density.