Method for eliminating stress of powder metallurgy integral intermediate case

The titanium alloy intermediate case is a case component with the most complex structure in a turbofan aero-engine and is also one of the most important main bearing components. High-precision, high-performance and high-quality integral manufacturing of the intermediate case can be achieved through a powder metallurgy forming method, but due to the fact that the structure is too complex, internal stress elimination becomes one of key links. The invention provides a stress relieving method for a powder metallurgy integral intermediate case, which is characterized in that creative researches are developed from multiple aspects such as progressive increase type fillet design at a transition joint, a symmetric sheath processing and removing method, an integral tightening type gradient high-temperature vacuum annealing method and a transition joint high-frequency point impact stress relieving method; and low-stress control of the whole powder metallurgy intermediate case is realized. 钛合金中介机匣是涡扇航空发动机内结构最为复杂的机匣类构件，也