Prediction of Thermal Mechanical Fatigue Properties of Ni-Base Single Crystal Superalloys

Abstract

  This study was carried out to find out the mechanical properties of nickel-base superalloys that affect thermal mechanical fatigue (TMF). TMF tests and high temperature tensile tests were conducted on 28 of Ni-base single crystal superalloys in order to obtain mechanical property data. Based on the experimental data, Multiple regression analysis was performed for the correlation between the number of TMF cycles to failure and the alloy compositions. The multiple correlation coefficient was found to be R=0.84; this indicates that alloy composition has a considerable relationship with the number of TMF cycles to failure. It was also found that the addition of Co, Ru and Al is effective to improve the TMF property.
   In addition, another multiple regression analysis was also carried out for the correlation between the number of TMF cycles to failure among high temperature mechanical properties and microstructural parameters.