Fatigue small crack growth threshold determination of a high-Nb TiAl alloy at different temperatures by in-situ observation  

作　　者：Min Zhang Xi-ping Song Long Yu Hong-liang Li Ze-hui Jiao Hui-chen Yu 

机构地区：[1]State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing [2]Testing Research Center for Aeronautical Materials,Beijing Institute of Aeronautical Materials

出　　处：《International Journal of Minerals,Metallurgy and Materials》2013年第12期1192-1197,共6页矿物冶金与材料学报（英文版）

基　　金：financially supported by the National Basic Research Program of China (No.2011CB605506)

摘　　要：The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy （SEM） in-situ observation. The results indicated that the fatigue crack growth threshold △Kth of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750℃ was determined as 12.89 MPa.m^1/2 and 8.69 MPa.m^1/2, respectively. The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored. At the same time, the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy （SEM） in-situ observation. The results indicated that the fatigue crack growth threshold △Kth of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750℃ was determined as 12.89 MPa.m^1/2 and 8.69 MPa.m^1/2, respectively. The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored. At the same time, the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.

关 键 词：titanium aluminum alloys NIOBIUM fatigue crack propagation high temperature testing 

分 类 号：TG115.57[金属学及工艺—物理冶金]