Method for manufacturing an abradable plate and repairing a turbine shroud

Abstract

The invention relates to a method for manufacturing an abradable plate (32) for a turbomachine turbine shroud (24, 26), the method comprising preparing a mixture comprising a cobalt- or nickel-based metal powder and a powder based on a fluxing element, depositing a layer of the powder mixture in a mold, and making the abradable plate (32) by subjecting the powder mixture layer to a method of SPS sintering.The invention also provides a method of preparing a turbine shroud (24, 26) for a turbomachine.

Description

BACKGROUND OF THE INVENTION[0001]The present disclosure relates to a method for manufacturing a turbine shroud for a turbomachine.[0002]In numerous rotary machines, it is now known to provide the ring of the stator with abradable tracks facing the tips of the blades of the rotor. Such tracks are made using so-called “abradable” materials, which, when they come into contact with rotating blades, become worn more easily than the blades themselves. This serves to ensure minimum clearance between the rotor and the stator, thereby improving the performance of the rotary machine, without running the risk of damaging the blades in the event of them rubbing against the stator. On the contrary, such rubbing erodes the abradable track, thereby acting automatically to match the diameter of the ring of the stator as closely as possible to the rotor. Thus, such abradable tracks are often installed in turbomachine compressors.[0003]In contrast, use of such tracks is less common in the turbines of...

AI Technical Summary

Benefits of technology

The patent text discusses the use of metal powders, specifically cobalt- or nickel-based powders, for high-temperature applications. These powders have the advantage of being abradable and providing a heat shield. The use of brazing to attach the abradable plate to the turbine shroud allows for the avoidance of depositing a new coating. The technical effect of this patent text is the improved performance and reliability of turbine components in high-temperature engines.

Problems solved by technology

Specifically, the burnt gas coming from the combustion chamber flows into the high-pressure turbine at very high levels of temperature and pressure, thereby leading to premature wear of conventional abradable tracks.

Nevertheless, under such circumstances, it can naturally be understood that the integrity of the blades is no longer ensured in the event of coming into contact with the stator, which makes it necessary to provide greater clearance between the rotor and the stator, and therefore increases the rate of leakage past the tips of the blades, thus reducing the performance of the turbine.

Furthermore, because of spots of rubbing against the blades and because of the temperature of the burnt gas, the coating can become damaged, thereby providing the stator with less protection.

Images