Effect of various 3D printing defects on the burst speed of functional gradient turbine disk

Currently, the quality control issue is still a key factor limiting the practical applications of three-dimensional (3D) printing materials and structures. For verification of turbine disk based on 3D printed functionally graded materials, firstly, based on the unified viscoplastic constitutive model with damage, the constitutive model with temperature term was established for high temperature blade material. Then, the burst speed was analyzed under the working temperature field based on the strain-based fracture criteria. The influence of 3D printing defects on the burst speed of the turbine disk was systematically explored, including pores, powder exhaust-holes, interfaces, and cracks. The research results indicate that the rate dependence and temperature softening effect of high temperature materials can be well described by the unified viscoplastic constitutive model considering the effect of temperature and material damage, and the defects located in the high-strain areas (critical sections) can lead to a significant decrease in the burst speed of the verification turbine disk and also cause the variation of fracture position. Considering all types of manufacturing defects obtained from inspection, the error between the simulation and experimental results of the burst speed is only 0.69%. It can provide guidance for the damage tolerance design of key components manufactured by 3D printing.