Effect of Thermal Barrier Coating Layer on HIP Treated IN738LC Fatigue Characteristic

The fatigue characteristic of thermal barrier-coated Ni-base superalloy IN738LC at room temperature was studied by fatigue test using SEM-servo testing machine. In order to eliminate the influence of micro-shrinkage in IN738LC and purely investigate the effect of TBC on fatigue characteristic, HIP treated IN738LC was used in comparison with NON-HIP treated one. The results indicate that HIP treatment is effective to remove micro-shrinkage and fatigue life is greatly improved. The TBC coating layer is a strength member in the small test specimen at room temperature, and TBC coated material showed lower fatigue life rather than IN738LC without TBC.