The creep damage caused by the centrifugal stress is one of the main failure mechanisms of the blade, so it is very important to study the creep deformation behavior of the nickel-based single crystal superalloy. Based on the typical service conditions of the single crystal blade, this paper reviews the creep deformation mechanisms under the conditions of the high temperature-low stress and the medium temperature-high stress. It is suggested to study the creep behavior of the single crystal superalloys with typical defects and the effect of the oxidation and the hot corrosion on the creep-fatigue deformation damage mechanism.

Since the introduction of the hot isostatic pressing (HIP) technology, it has been widely used in the powder metallurgy forming to improve the densification of castings. With the increasing demand for the high performance nickel-based single crystal superalloys, the applications of the hot isostatic pressing in the nickel-based single crystal superalloys attracted more and more studies. This paper reviews the current research progress in the applications of the hot isostatic pressing for the high temperature nickel-based single crystals, focusing on the elimination effect of the hot isostatic pressing on the looses and other pore defects in the nickel-based single crystal superalloys, and the pore healing mechanism, as well as the changes in mechanical properties such as tensile strength, endurance, and fatigue after applying the hot isostatic pressing. The application of the hot isostatic pressing for the restoration of the mechanical properties of the serviced parts and the calculation simulation in guiding the heat and other topics are also discussed. The role of the static pressure process research, and the future development of China's hot isostatic pressing technology are commented.

The Cobalt-based superalloy enjoys a high strength and a good heat and corrosion resistance, with a wide range of applications in biomedicine, aerospace and other fields. In recent years, the rapid development of the additive manufacturing technology represented by the selective laser melting technology (SLM) has provided new possibilities for the processing and the application of high-temperature alloys such as the cobalt-based superalloys. Compared with the traditional processing methods, the additive manufacturing technology has many advantages, such as the customization, the fairly easy processing of complex structural parts and the short manufacturing cycle. This paper reviews the applications of the selective laser melting (SLM) technology in the preparation of the cobalt-based superalloys, as well as the tests for the density and mechanical properties, and the influence of the process parameters on the density, the hardness and other mechanical properties such as the roughness, the tensile strength. In order to meet the actual use demand, the postprocessing might be needed and the influence of the postprocessing should be considered.

The development and the application of the additive manufacturing technology are discussed in this paper, as well as the characteristics of the additive manufacture. The types and the characteristics of the defects formed during the additive manufacturing process are analyzed. Various non-destructive testing (NDT) methods, such as the ultrasonic testing, the computed tomography, the eddy inspection and the infrared camera measurement are used for the additive manufacturing parts, their applicability, the merits and weaknesses are analyzed. Finally, it is suggested that for the additive manufacturing parts, some new NDT methods and the online monitoring technology should be developed, and the related NDT standards should be established.