Lattice Parameters and Effects Factors of Single Crystal Nickel-base Superalloy

By means of microstructure observation and XRD diffraction analysis,an investigation has been made into the influence of the element Re on the lattice parameters and misfits of the single crystal nickel based superalloys.Results show that,after full heat treated,microstructure of 2%Re suprealloy consists of the cubic γ' phase with the size about 350-400nm embedded coherently in the γ matrix phase.In XRD patterns of the superalloys with γ',γ phases,the asymmetry reason of XRD peaks is attributed to the overlap of the peaks of γ' and γ phases.It is shown by analyzing XRD patterns of the alloys at different conditions that the lattice parameters of γ',γ phases at room temperature increases slightly,and absolute values of the lattice misfit decrease slightly with the increase of the element Re content.And the parameters of the γ',γ phases and absolute values of the misfits increases with temperatures elevated.And in the further,the thermal expansion coefficient of γ' and γ phases at different temperature interval are calculated.