Nickel based single crystal superalloy has become the main material for the manufacture of advanced aero-engine and gas turbine blades due to its excellent high temperature mechanical property and microstructure stability. The anisotropy of mechanical property for nickel based single crystal superalloy is very important for the service property,safety and reliability of turbine blades,which has been highly valued by turbine blade designers and manufacturing experts. In order to meet the more stringent application requirements,new nickel based single crystal superalloys have been constantly developed at home and abroad to improve the temperature bearing capacity of aero-engine blades. However,the research on the anisotropy of mechanical property for new alloys is not very comprehensive,and the mechanism of newly added elements needs to be further studied. In recent years,the research at home and abroad shows that the anisotropy of mechanical property for nickel based single crystal superalloy is related to temperature,stress and other factors. Meanwhile,different single crystal superalloys show different laws of anisotropy. The tensile property of nickel based single crystal superalloy has obvious anisotropy. With the increase of temperature,the ability of atomic diffusion and the number of slip systems increases,and the anisotropy of tensile property decreases. With the increase on the content of refractory elements in the alloy composition,the dislocation cross-section probability or deformation compatibility of the slip system will change,showing different tensile anisotropy. Under the condition of medium temperature and high stress,there is significant anisotropy in creep property. With the increase of stress, the creep property of the alloy with [001]orientation decreases significantly,and the creep property of the alloy with [111]orientation changes little,which is related to the effect of stress change on the number of slip systems. With the increase on the content of refractory elements,it is easier to start the slip systems with different orientations and form stacking faults,which affects the anisotropy of creep property. Under the condition of high temperature and low stress,the anisotropy of creep property is weakened,the creep property of the alloy with [111]orientation is better,and the creep property of the alloy with [001]and [011]orientation is poor. The low cycle fatigue property of nickel based single crystal superalloy also has obvious anisotropy. The fatigue life of the alloy with [001]orientation is the longest,followed by the alloy with [011]orienta-tion,and the alloy with [111]orientation is the shortest. The high cycle fatigue property decreases in the order of [111],[001]and [011] orientation,which is mainly related to the elastic modulus,the number of slip systems and Schmid factor. This article introduces the research progress on anisotropy of mechanical properties such as tensile,creep and fatigue property of nickel based single crystal superalloys in detail. The failure mechanism of alloys with different crystal orientations is revealed. The problems of the anisotropy of new nickel-based single crystal superalloy are stuclied and its prospects are discussed. The purpose is to provide a useful reference for the application of nickel base single crystal superalloy in aero-engine turbine blades in the future. © 2022 Cailiao Daobaoshe/ Materials Review. All rights reserved.
