Effect Of Electrostatic-field Treatment On The Diffusion And Segregation Behaveors Of The Solute Atoms In GH4169Superalloy

Superalloy is a kind of key metal material with magnificent high temperature strength and remarkable overall performance, and a marking level of industry and National Defense. In order to cover the booming of requirements of materials in aircraft industry, scientists try to discover a new method for develop materials’ properties. The electromagnetic field, as a powerful and controllable external field, has been received more attention in the past years.When Electric field is combinated with the other fields such as the temperature field, it shows many special coupling effects. Present research makes the commercial nickel-based superalloy GH4169as the experimental material. The effects of electrostatic-field treatment on distributions of solute atoms, types and concentration of vacancy and the size and quantity of second-phase were investigated, and the effect mechanism had been discussed.Based on distribution graph of mass fraction of solute atoms, microhardness, vacancy concentration, it was found that two laws of electrostatic-field treatment existed. Firstly, the segregation of the solute atoms could be changed with the increase of the electrostatic field intensity, and when reaching maximum or minimum degree, the segregation would be into reverse. Secondly, it was found that effects of electric-field treatment on segregation of the solute atoms and microhardness be related to the location in electrostatic-field.The result shows that there are two diffusion mechanisms of solute atoms during electrostatic-field treatment. Firstly, it was found that Chromium atoms could trap vacancies and then turned into compound in order to reduce lattice distortion, and then the compounds of Chromium atoms and vacancies would move to the surfaces of specimen. Scondly, when electrostatic field intensity is low, Ferrum atoms be inclined to move to the surfaces of specimen in the form of the compounds because of the effect its atomic radius; when electrostatic field intensity was high, Ferrum atoms would move in the opposite direction of the vacancies by exchanging places with each other, because of the low diffusion activation energy.