Influence of electrostatic field treatment on microstructures and mechanical properties of GH4169 superalloy

An external electrostatic field treatment (EFT) was applied to GH4169 alloy with standard heating treatment. The internal friction and room temperature (RT) tensile test were conducted for both the electrostatic field treated and standard heating treated alloys in order to investigate the variations of microstructure and mechanical properties of the alloy with the EFT. The experimental results demonstrated that the EFT remarkably enhanced the formation of interstitial atoms and vacancies. During the tensile deformation at RT under the strain rate of 10(-2) or 10(-4) s(-1), the dislocation slip could be evidently hindered by the large numbers of interstitial atoms in the matrix, contributing to a great increase in the yield and tensile strengths of the electrostatic field treated alloy. By EFT, the dislocation configuration of deformed alloy was primarily the single slip instead of the crossslip in the standard heating treated alloy, resulting in the increasing of grain deformation capacity by more vacancies.