Análise da condutividade elétrica por meio do ensaio de correntes parasitas da liga Waspaloy submetida a tratamento térmico

Abstract

The demand for new electrical energy sources and the reuse of injurious gases have been reinvented the market. The gas turbines are part of this revolution and the materials of their components are being developed to grow up the energy production efficiency. In this paper, the relationship between electrical conductivity and hardness of a Nickel superalloy, named Waspaloy, thermally treated by aging, will be analyzed by Eddy Current non-destructive test and, also, the destructives methods of Vickers microhardness, optical microscopy and scanning electron microscopy. The Eddy Current test showed a significant variation of electrical conductivity between the samples without heat treatment and with heat treatment, not differentiating these with the thermally treated samples and coated with titanium aluminum nitride. The Vickers microhardness test determined that the thermally treated samples were harder than the untreated samples. The optical microscopy showed the movement of precipitates present dispersed in the untreated alloy and then concentrated in the grain boundaries of the part submitted to heat treatment. The scanning electron microscopy was able to determine more accurately the phases present in the samples and how the intermetallic precipitates were grouped in the grain boundaries. All changes detected by the four tests validate the Eddy Current test as an effective method in the analysis of the electrical conductivity of heat treated Waspaloy superalloy parts.