GH36合金中M<sub>23</sub>C<sub>6</sub>、VC的界面结构

GH36合金中M₂₃C₆、VC的界面结构

摘要: 使用透射电镜观察了GH36合金中M₂₃C₆、VC碳化物和基体之间的界面结构,在M₂₃C₆/γ的半共格界面上分布有错配位错列,间距约10nm。根据\rm\vec g·\rm\vec b=0判据,可以确定该位错的Burgers vector \rm\vec b=a/2(110)γ,VC/γ的相界面是具有很大点陈错配度(δ=+0.155)的共格界面。最后,从M₂₃C₆、VC和基体之间的不同界面结构与性质讨论了以碳化物沉淀为主要强化手段的Fe基GH36合金的强韧化本质以及如何识别波纹图(Moire pattern)和界面位错的问题。

Abstract: 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.