Methods of Applying Thermal Barrier Coatings

Abstract

To apply the thermal barrier coating (10), a plasma jet (5) is generated in the working chamber (2) by a plasma torch and directed towards the surface of the substrate (3) introduced into the working chamber, where it is deposited on the substrate by PS‑PVD A ceramic coating is applied to the surface, wherein the coating is injected as a powder into the plasma jet and partially or completely vaporized therein. When applying a thermal barrier coating, in the first working step, the feed rate of the injected powder is set such that most of the injected powder is vaporized, wherein the coating condenses from the gas phase onto the surface of the substrate and is bonded to the surface of the substrate. The materials form a mixed phase. In a second working step, the feed rate of the infused powder is increased by at least 5 times, so that the relative proportion of vaporized infused powder is reduced and the coating is deposited in the form of elongated columns, which create an anisotropic microstructure and are oriented substantially perpendicular to the substrate surface.

Description

technical field [0001] The invention relates to a method for applying a thermal barrier coating on the surface of a substrate according to the preamble of claim 1 and to a substrate with such a thermal barrier coating. Background technique [0002] Thermal barrier coatings are used in machinery and processes to protect components subjected to high thermal strains from heat, hot gas corrosion and erosion. Increases in mechanical and process efficiency can often only be achieved by increasing process temperatures, so that exposed components must be protected accordingly. Thus, turbine blades, for example in aeroengines and stationary gas turbines, are often provided with thermal barrier coatings or multi-layer thermal barrier coating systems to protect the turbine blades from thermal process temperatures and to extend maintenance intervals and service life . [0003] Depending on the application, thermal barrier coating systems may comprise one or more layers such as barrier...

AI Technical Summary

Problems solved by technology

Thin thermal barrier coatings applied by APS have the disadvantage that they have relatively low stretch tolerance and tend to peel off under cyclic thermal strain

[0013] However, the preparation of the thermal barrier coating structure described in US 5,238,752 has the following disadvantages: the equipment cost for applying the thermal barrier coating by EB-PVD is relatively high, and the application speed is low, so that the application by EB-PVD Applying a thermal barrier coating is relatively expensive

Images