Search Results for bond coat oxidation

This article discusses some of the newer thermal barrier coating materials being considered for use in gasified coal-based turbines and how they compare with conventional materials in terms of bond coat oxidation and topcoat damage due to particle erosion and molten ash deposits.

New thermal and cold spray technologies are being developed to extend the lifespan of thermal barrier coating (TBC) systems at elevated temperatures. This article describes the relevant attributes of coating technologies such as high velocity air fuel, high velocity air plasma spray, and high pressure cold spray for use in TBC systems.

Clearance-control coatings play a major role in gas turbine engines by minimizing the air gap between rotating blade tips and engine casings. An improvement of just 125 µm can reduce fuel consumption by 0.5%. This article discusses the potential impact of new materials being considered for blade tip coating systems, including NiCoCrAlY bond coats and matrix layers with Hf, Re, or Si additions for better oxidation and creep resistance, embedded angular CBN particles for enhanced incursion of abradable shroud coatings, and double or Pt aluminide topcoats for extended oxidation protection.

This article discusses the influence of water vapor on the performance of YSZ thermal barrier coatings, particularly the oxidation resistance of the bond coat.

Increasing and controlling particle impact temperature is proving to be beneficial for both process performance and coating properties.

This article describes the development and evaluation of a novel atmospheric plasma spray torch designed to overcome limitations in coating internal diameter surfaces. A case study demonstrates the torch's effectiveness in producing high-quality thermal barrier coatings (TBCs) for turbine components, applying NiCoCrAlY+HfSi bond coats and 8 wt% YSZ topcoats with appropriate porosity levels. Analysis results confirm that this torch delivers comparable performance to conventional torches while enabling the critical capability of operating in confined geometries, addressing a significant gap in thermal spray applications for gas turbine engine components subjected to extreme operating conditions.

This new article series explores the indispensable role of characterization in the development of cold spray coatings and illustrates some of the common processes used during coatings development. This article provides a list of techniques to be covered in subsequent articles.

A high-velocity oxyfuel (HVOF) spray gun that operates on conventional (gas or kerosene) fuels as well as liquid-gas combinations is shown to be capable of producing MCrAlY bond coats consisting of a rough surface layer (for adhesion) on a dense base (for oxidation protection).

This article series explores the indispensable role of characterization in the development of cold spray coatings and illustrates some of the common processes used during coating development.

This article series explores the indispensable role of characterization in the development of cold spray coatings and illustrates some of the common processes used during coating development.

The use of coatings to enhance the performance of components is one of the most powerful tools in materials engineering. This article highlights some examples of how thermal spray technologies are used to enhance surface properties for selected applications and industries.

The absence of standards and a common vocabulary are an obstacle when it comes to evaluating the structure of thermal spray coatings. However, proper sectioning and mounting of metallographic specimens helps ensure that the images obtained accurately reflect the coating structure and the information that can be derived from it.

This article presents a brief overview of thermally sprayed thermal barrier coatings (TBCs) used in gas turbines that generate electrical power.

Cold spray is an effective method of depositing a variety of temperature-sensitive materials in specialized applications, such as high-value aerospace component repair. The use of cold spray has seen a significant increase in the repair and restoration of housings for integrated drive generators used in commercial aircraft.

Aerosol deposition offers an alternative to conventional thin film processes when mesoscale coatings are needed. The process is being used to create readily integrated, high density ceramic and metallic thick films on a variety of substrates at room temperature.

Thermal spray plays an important but latent role in many energy generation applications. Strong R&D commitment is required to further expand its technological envelope. This article addresses future directions in the use of thermal spray coating technologies in the energy sector.

This case study reviews the considerations in applying plasma spray thermal barrier coatings on augmenters used in military aircraft turbine engines to extend their service life.

This article series explores the indispensable role of characterization in the development of cold spray coatings. Transmission electron microscopy is used to understand powder characteristics, cold spray coating deformation behavior both within splats as well as near the coating-substrate interface, phase transformations in the as-sprayed and heat treated conditions, phase equilibria of the coating under the operating conditions pertaining to the application of the coating, the coating recovery mechanism, and the thermal stability of the coating.

A multicomponent thermal spray coating system resists pick-up of contaminants that can cause flaws on heat treated strip surface.

A new fusion cladding process that uses high-intensity arc lamps can produce pinhole free, smooth, uniform coatings as thick as 15 mm from various feedstock materials. This article briefly describes the process and the corrosion, wear, and high-temperature behavior of fusion claddings designed for oil and gas pipelines and related components.