Influence of surface calorizing of TMN-B1 intermetallic alloy on the resistance to high-temperature oxidation and gas corrosion

The high-temperature gas corrosion of intermetallic alloys based on titanium aluminides is investigated at 800°C after calorizing. The composition and structure of the surface layer are studied after the tests     

Estimating the repairability of blades used in gas pumping units

Results obtained from a study of the postoperation state of the blades (after they had been in operation for up to 56000 h) used in the high-pressure turbine of a GTK-25IR gas pumping unit made of ZMI-3U and In738 nickel alloys with protective coatings applied on the cuter surface of the blade and in its inner cavity are presented. It is shown that the blades can be repaired with taking into account structural and phase changes occurring in alloys and coatings. The boundary conditions regarding the possibility of carrying out repair and restoration works are determined depending on the time for which the blades have been in operation.     

High-Temperature Corrosion of Nickel Alloy TsNK7P with a Protective Aluminide Coating

Comprehensive studies aimed at developing a procedure for accelerated corrosion tests and investigating the high-temperature gas corrosion of a nickel alloy TsNK7P with an aluminosilicide coating were carried out. The kinetics and peculiar properties of the corrosion process were studied.     

Quality of Turbine Blades after Electrolytic Plasma Removal of an Aluminide Coating

Dimensional and shape errors of nickel-alloy components after electrolytic plasma treatment are considered.     

Some Features of High-Temperature Oxidation of Aluminide Coatings on Alloy TsNK-7P

Special features of high-temperature oxidation of aluminide coatings (slip-deposited Al – Si and ion-plasma-deposited VSDP-11) on alloy TsNK-7P are considered. The kinetics of the oxidation process, the element composition, and the microhardness of coatings with different thicknesses are described. Results of thermal fatigue tests of alloy TsNK-7P with aluminide diffusion coatings are presented. It is shown that the VSDP-11 coating ensures a higher heat resistance and thermal fatigue strength on alloy TsNK-7P than the Al – Si coating and can replace the latter on turbine vanes of gas compressor units.     

Effect of implantation of ytterbium ions into the surface of a nickel alloy on the composition and structure of VSDP-11 vacuum-plasma coating

The structure and the phase composition of VSDP-11 vacuum plasma coating formed on TsNK-7P nickel alloy after preliminary implantation of the surface with ytterbium ions and the changes in the concentration of chemical elements over the thickness of the protective coating are considered. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 40–44, July, 2007.     

On the Removal of Aluminide Coating from Blades of Gas Turbin Engine

The peculiarities of removing -11 coating from 32 type alloy in an acidic etching bath depending on the concentration and ratio between the amounts of potassium bichromate and ammonium heptamolybdate additives are studied with gravimetrical and electrochemical methods. The results are explained by the peculiarities of bichromate and molybdate ions adsorption at the surface and their oxidizing properties. Baths providing sufficiently quick removal of the coating at a minimum alloy surface etching are recommended.