Platinum-Nickel Aluminizing Coating Process for Turbine Components

Solution Overview

Problem

The existing method for depositing an aluminizing coating on high-temperature parts, such as turbine vanes or nozzles, is lengthy and costly due to the need for a diffusion treatment of platinum, which forms PtAl2 plates that reduce the coating's effectiveness.

Innovation Solution

A method involving the sequential deposition of a platinum-nickel layer and an aluminum layer without diffusion, using electrolysis for platinum and nickel deposition, and aluminum chemical vapor deposition (CVD) for the aluminum layer, reducing the process duration and cost while ensuring effective NiAl compound formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a diffusion treatment is performed to prevent PtAl2 plate formation, then the protective effectiveness of the coating is improved, but the process duration and cost increase significantly

Engineering Contradiction:

Improveprotective effectivenessVSAvoidprocess duration

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by depositing a nickel-containing layer (containing at least 35% nickel) on the substrate surface before aluminum deposition. This pre-deposited nickel layer is strategically positioned to prevent PtAl2 plate formation during subsequent aluminum deposition, eliminating the need for lengthy post-deposition diffusion treatments while maintaining coating effectiveness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent extracts the diffusion step from the conventional aluminizing process. Instead of performing diffusion treatment after aluminum deposition to prevent PtAl2 formation, the method removes this unnecessary step by pre-depositing nickel, which passively prevents PtAl2 formation from the outset, thereby reducing process duration and cost.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If a diffusion treatment is performed to prevent PtAl2 plate formation, then the protective effectiveness of the coating is improved, but the manufacturing cost increases

Engineering Contradiction:

Improveprotective effectivenessVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by depositing a nickel-containing layer (containing at least 35% nickel) on the substrate surface before aluminum deposition. This pre-deposited nickel layer is strategically positioned to prevent PtAl2 plate formation during subsequent aluminum deposition, eliminating the need for lengthy post-deposition diffusion treatments while maintaining coating effectiveness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent extracts the diffusion step from the conventional aluminizing process. Instead of performing diffusion treatment after aluminum deposition to prevent PtAl2 formation, the method removes this unnecessary step by pre-depositing nickel, which passively prevents PtAl2 formation from the outset, thereby reducing process duration and cost.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If platinum is deposited in high quantity to ensure coverage, then the surface protection is improved, but the cost and material usage increase

Engineering Contradiction:

Improvesurface protectionVSAvoidplatinum usage

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating a composite layer with specific nickel content (at least 35% nickel) at the substrate interface, rather than uniformly distributing platinum throughout. This localized nickel enrichment zone specifically targets the region where PtAl2 formation is problematic, reducing overall platinum requirements while maintaining protective effectiveness.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining platinum with nickel in a specific ratio (at least 35% nickel) to create a composite layer with optimized properties. This composite structure leverages nickel's ability to suppress PtAl2 formation while reducing platinum consumption, achieving cost-effective surface protection.

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach shortens the coating deposition time and reduces costs by eliminating the diffusion step, while maintaining or improving the protective properties of the aluminizing coating by directly forming NiAl compounds within the aluminum layer, thus preventing PtAl2 plate formation.

Implementation Method 1

A layer containing platinum and at least 35% of nickel is deposited on a surface of the substrate

Methodology Applied

Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

aluminum chemical vapor deposition (CVD) for the aluminum layer

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Implementation Method 3

the nickel that has diffused in the layer of platinum 20 diffuses in the layer of aluminum 40, where it forms NiAl compounds 60

Methodology Applied

Scientific EffectDiffusion: Diffusion

Data Source

PatentUS10183311B2Method for aluminizing a surface by means of the advance deposition of a platinum and nickel layer

Publication Date: 2019.01.22 SAFRAN AIRCRAFT ENGINES SAS

AI summary

A method for depositing an aluminizing coating onto a substrate. The method includes: (a) depositing a layer, containing platinum and at least 35% of nickel, onto a surface of the substrate; and (b) depositing an aluminum coating onto the layer.