Nickel-Based Blade Repair Composition for Porosity-Free Restoration

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Solution Overview

Problem

Existing nickel-based superalloy repair methods using high-concentration B, Zr, and Hf as melting-point depressants result in the formation of boride brittle phases and low-melting-point eutectic phases, leading to decreased mechanical properties and limited applicability under high-stress conditions, and premature failure of blade coatings.

Innovation Solution

An activator comprising specific percentages of Cr, Co, Al, Ti, Nb, and Ru, prepared by the rotating electrode method, is used to regulate the alloying elements' proportion, avoiding the formation of harmful phases and enhancing high-temperature mechanical properties by promoting microstructural stability and creep resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If high-concentration B, Zr, and Hf are introduced as melting-point depressants to ensure complete liquefaction of the solder below the base material's melting point, then the processability of the solder is guaranteed, but large differences in elemental composition and microstructure between the solder and base material occur, leading to formation of boride brittle phases and low-melting-point eutectic phases

Engineering Contradiction:
Improvesolder processabilityVSAvoidelemental composition and microstructure uniformity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The invention changes the chemical composition parameters of the activator by strictly limiting the content of B, Zr, and Hf to specific ranges (B: 0.01-0.05wt%, Zr: 0.01-0.05wt%, Hf: 0.01-0.05wt%). This parameter control prevents excessive formation of harmful phases while maintaining the activator's ability to lower melting point sufficiently for the repair process to work effectively.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the melting point of the solder is suppressed by introducing high concentrations of B, Zr, and Hf to guarantee processability, then the solder can be completely liquefied at a temperature lower than the initial melting point of the base material, but boride brittle phases and low-melting-point eutectic phases rich in B, Zr, and Hf are formed

Engineering Contradiction:
Improvesolder liquefaction temperatureVSAvoidhigh-temperature mechanical properties
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The invention optimizes the concentration parameters of melting-point depressants by limiting B, Zr, and Hf to 0.01-0.05wt% each. This controlled composition achieves sufficient melting point depression for processability while preventing excessive formation of brittle phases, thereby preserving high-temperature mechanical properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The activator is designed as a composite material containing multiple alloying elements (Cr, Co, Al, Ti, Nb, Ru, and controlled amounts of B, Zr, Hf) that work synergistically. This composite composition achieves the desired melting point depression and microstructural control without relying on high concentrations of single harmful elements.

Inventive Principle:
Principle #40Composite materials

3Temperature

If the solution heat treatment temperature is reduced to prevent the morphological and property remodeling area from remelting, then the harmful low-melting-point phases do not melt, but the blade substrate does not reach the best restoration heat treatment effect, resulting in a decrease in the mechanical properties of the substrate

Engineering Contradiction:
Improvesolution heat treatment temperature controlVSAvoidsubstrate mechanical properties
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The invention changes the compositional parameters of the activator to contain controlled amounts of B, Zr, and Hf (0.01-0.05wt% each), which raises the melting point of the repair material compared to conventional high-concentration formulations. This compositional adjustment enables solution heat treatment at the standard temperature of 1130°C without remelting the repair area, thereby achieving both phase stability and optimal substrate restoration.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If B in the morphological and property remodeling area diffuses to the coating during the service process, then the coating fails prematurely, but this diffusion process cannot be completely prevented

Engineering Contradiction:
Improveblade coating service lifeVSAvoidB diffusion to coating
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The invention changes the B content parameter in the activator to a controlled low range (0.01-0.05wt%). This reduced concentration of B in the repair material significantly decreases the amount of B available for diffusion into the coating during service, thereby extending coating life and preventing premature failure.

Inventive Principle:
Principle #35Parameter changes

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

The solution effectively improves the high-temperature mechanical properties and creep resistance of the morphological and property remodeling area, ensuring the microstructure matches the base material, preventing porosity, and maintaining the integrity of the repair under high-stress conditions.

Implementation Method 1

Based on the principle of isothermal solidification, this technology can effectively avoid the generation of hot cracks in the repair area

Methodology Applied
Scientific EffectIsothermal solidification: Phase Change

Implementation Method 2

The activator is prepared by the rotating electrode method

Methodology Applied
Scientific EffectRotating electrode method: Electrodeposition

Data Source

PatentEP4729643A1Activating agent, repairing agent and repairing method for blade damage defects for shape and performance restoration
Publication Date: 2026.04.22 DONGFANG TURBINE CO LTD
  • EP4729643A1 patent drawingFigure 1~2
  • EP4729643A1 patent drawingFigure 3~4
  • EP4729643A1 patent drawing

AI summary

The present invention relates to the technical field of nickel-based high-temperature alloy restoration Disclosedare an activating agent, repairing agent and repairing method for blade damage defects for shape and performance restoration. The activating agent at least comprises the following elememts in percentage by mass: Cr(16.1%-19.8%),Co(9.2%-12.8%),Al(1.2%~2.7%),Ti(9.6%-11.7%),Nb(5.6%~7.3%),Ru(4.6%-5.8%) and Mg(0.005%-0.01%). The repairing agent comprises an activating agent,a curingagent, and an adhesive which are umiformly mixed at a raio.Accordingto the present invention, the creep resistance and mechanical propertics of an alloy at high temperature can be effetively improved,and generation of a large amount of pores in a shape and performance restoration area caused by a capilary channel being solidified and closed in advance can be effectively prevented.