Effect of Electric Field Treatment on Vacancy of Inconel 718 Superalloy at 1073 K

Effect of electric field treatment with different intensities on vacancy of Inconel 718 aged at 1073 K was investigated. The positron annihilation lifetime (PAL) and corresponding concentration of vacancies were measured by positron annihilation technique. It was found that atomic vibration at lattice site can be promoted by an external electric field performed on Inconel 718 superalloy during aged at elevated temperature. Some atoms owing the higher vacancy formation energy or larger radius will jump out from the normal lattice sites and form defects, which is leading to the increase of PAL of monovacancy. Under continuous effect on electric field, monovacancies will transform to three-dimensional vacancies of lower energy and vacancy clusters. Moreover, the vacancy concentration of Inconel 718 superalloy can be improved evidently by electric field treatment, and the average PAL of vacancies can be up to 6.3% when the electric field intensity is up to 8 kV/cm, which is very useful for controlling the microstructures evolution and properties of the superalloy, such as solute redistribution and precipitations.

[1]  A. P. Druzhkov,et al.  Positron annihilation studies of microstructural changes in cold-worked Fe–Ni-base aging alloys , 2010 .

[2]  H. Cai,et al.  High temperature deformation behavior of the TC6 titanium alloy under the uniform DC electric field , 2010 .

[3]  C. Kuo,et al.  Aging effects on the microstructure and creep behavior of Inconel 718 superalloy , 2009 .

[4]  K. Sakai.  An overlooked electrostatic force that acts on a non-charged asymmetric conductor in a symmetric (parallel) electric field , 2009 .

[5]  J. Kuriplach,et al.  Positron annihilation in vacancies at grain boundaries in metals , 2008 .

[6]  G. Ma,et al.  Effect of an electric field applied during the quenching on hardness of carbon steel , 2008 .

[7]  E. Gomaa,et al.  A study of annealing stages in Al–Mn (3004) alloy after cold rolling using positron annihilation lifetime technique and Vickers microhardness measurements , 2003 .

[8]  M. Weaver,et al.  Activation energy calculations for discontinuous yielding in Inconel 718SPF , 2001 .

[9]  H. Conrad,et al.  Influence of an external electric field during quenching on the hardenability of steel , 2001 .

[10]  Y. Baranov.  Effect of electrostatic fields on mechanical characteristics and structure of metals and alloys , 2000 .

[11]  Weixing Chen,et al.  DEPENDENCE OF CREEP FRACTURE OF INCONEL 718 ON GRAIN BOUNDARY PRECIPITATES , 1997 .

[12]  H. Conrad,et al.  Whisker formation and the mechanism of superplastic deformation , 1996 .

[13]  K. Yokogawa,et al.  Boundary in γ″ precipitates in inconel 718 nickel-base superalloy , 1995 .

[14]  A. Sprecher,et al.  EFFECT OF ELECTRIC FIELD ON CAVITATION IN SUPERPLASTIC ALUMINUM ALLOY 7475 , 1991 .

[15]  A. Sprecher,et al.  Superplastic deformation behavior of 7475 aluminum alloy in an electric field , 1990 .

[16]  A. Sprecher,et al.  Increased hardenability of steel by an external electric field , 1990 .

[17]  G. P. Tiwari,et al.  A correlation between vacancy formation energy and cohesive energy , 1975 .