HIGH TEMPERATURE CREEP AND FATIGUE BEHAVIOR AND LIFE PREDICTION METHOD OF A TiAl ALLOY
Creep (at 700 ℃) and low cycle fatigue (at 700 and 750 ℃) tests of Ti-43Al-9V-Y alloy with duplex (DP) and fully lamellar (FL) microstructures are carried out to study the creep,fatigue deformation and life prediction.Firstly,Omega method is employed to characterize the creep deformation and to predict the rupture life.Secondly,the proposed fatigue life model based on walker strain is employed to predict the fatigue life for these two types of TiAl alloy.The results show that:(1) high temperature creep curves of the material of both DP and FL microstructure contain steady and accelerated creep stages other than initial creep stage,and Omega method is able to characterize the creep deformation of TiAl alloy with DP and FL microstructure; (2) the rupture time of the material of FL microstructure is longer than that of DP microstructure,and the predicted rupture time by Omega method agrees well with the test data; (3) the fatigue life of DP is longer than that of FL under the same test condition,and the predicted fatigue life is well located in the scatter band of 3 of the test fatigue life.
NETL
NSTL
万方数据
维普
