Formation of μ phase during thermal exposure and its effect on the properties of K465 superalloy

Specimens of K465 superalloy were thermally exposed at 950 and 1050 °C. μ phase precipitated in the form of needles or platelets. μ phase did not produce multiple internal cracks or interfacial decohesion during the room temperature tensile and high temperature stress rupture tests. On the contrary, μ phase produced a large plastic deformation showing the high ductility. μ phase played an insignificant role in the reduction of high temperature stress rupture lives and room temperature tensile ductility; thus, it did not affect the room temperature tensile and high temperature stress rupture properties of K465 alloy.