Thermal cycling creep properties of a directionally solidified superalloy DZ125  

作　　者：Wenrui An Satoshi Utada Xiaotong Guo Stoichko Antonov Weiwei Zheng Jonathan Cormier Qiang Feng 

机构地区：[1]Beijing Advanced Innovation Center for Materials Genome Engineering,State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China [2]Institut Pprime,UPR CNRS 3346,Department of Physics and Mechanics of Materials,ISAE-ENSMA,BP40109,86961 Futuroscope Chasseneuil Cedex,France [3]China Electronic Product Reliability and Environmental Testing Research Institute,Guangzhou 510610,China [4]Department of Microstructure Physics and Alloy Design,Max-Planck-Institut für Eisenforschung GmbH,Düsseldorf 40237,Germany

出　　处：《Journal of Materials Science & Technology》2022年第9期269-284,共16页材料科学技术（英文版）

基　　金：supported by the“National Key Research and Development Program of China(Grant No.2016YFB0701403)”;the“National Natural Science Foundation of China(Grant Nos.51631008 and 91860201)”;the“111 Project(No.B170003)”;financial support to the reported work.Stoichko Antonov would like to acknowledge financial support from the Alexander von Humboldt Foundation。

摘　　要：Aero-engine turbine blades may suffer overheating during service,which can result in severe microstructural and mechanical degradation within tens of seconds.In this study,the thermal cycling creep under(950℃/15 min+1100℃/1 min)-100 MPa was performed on a directionally solidified superalloy,DZ125.The effects of overheating and thermal cycling on the creep properties were evaluated in terms of creep behavior and microstructural evolution against isothermally crept specimens under 950℃/100 MPa,950℃/270 MPa,and 1100℃/100 MPa.The results indicated that the thermal cycling creep life was reduced dramatically compared to the isothermal creep under 950℃/100 MPa.The plastic creep deformation mainly occurred during the overheating stage during the thermal cycling creep.The thermal cycling creep curve exhibited three stages,similar to the 1100℃isothermal creep,but its minimum creep rate occurred at a lower creep strain.The overheating events caused severe microstructural degradation,such as substantial dissolution ofγ'phase,earlier formation of raftedγ'microstructure,widening of theγchannels,and instability of the interfacial dislocation networks.This microstructural degradation was the main reason for the dramatic decrease in thermal cycling creep life,as the thermal cycling promoted more dislocations to cut intoγ'phase and more cracks to initiate at grain boundaries,carbides,and residual eutectic pools.This study underlines the importance of evaluating the thermal cycling creep properties of superalloys to be used as turbine blades and provides insights into the effect of thermal cycling on directionally solidified superalloys for component design.

关 键 词：Directional solidified superalloy Thermal cycling creep OVERHEATING Creep properties Microstructural degradation 

分 类 号：TG132.3[一般工业技术—材料科学与工程]