Interfacial Structure of M₂₃C₆/γ and VC/γ in GH36 Superalloys

A TEM study on the interfacial structure of M₂₃C₆/γ and VC/γ precipitated in GH36 superalloys was conducted. The misfit dislocation distribution has been clearly observed at the semi-coherent interfaces of M₂₃C₆/γ, a single array along the broadfaces at both sides with Burgers Vector a/2 <110>γ and spaced about 10 nm apart. It has been shown circular strain field constrast around the very fine dispersive VC particles of 3 to 12nm or so in size. In addition, strengthening mechanism of M₂₃C₆ and VC precipitated in GH36 superalloy, and how to identify the moire pattern or interfacial dislocations by TEM, were also discussed.