Turbine Blade Platform Repair Using EDM and Laser Metal Deposition

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Solution Overview

Problem

Current methods for repairing deteriorated turbine blade or vane platforms in gas turbine assemblies, such as tungsten inert gas welding and laser cladding, face challenges like high heat affected zones, distortion, and defects like porosity and lack of fusion, due to inefficient removal and rebuilding processes.

Innovation Solution

The method involves using electro discharging machining to create a recessed zone with specific angled planes on the deteriorated area, followed by additive manufacturing with five axes laser metal deposition technology to rebuild the platform, optimizing the rebuilding process and avoiding common defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If tungsten inert gas welding is used to rebuild the platform, then the deteriorated zone can be repaired, but a large heat affected zone is created leading to gross distortion and loss of structural integrity

Engineering Contradiction:

Improveplatform repairabilityVSAvoidstructural integrity

Core Design Contradiction:

Ease of repairVSStrength

Solution Approach 1:

The patent replaces conventional tungsten inert gas welding with laser cladding technology. The laser beam delivers concentrated thermal energy with precise spatial control, creating a minimal heat affected zone compared to the broad thermal field of arc welding. This substitution enables repair while preserving the mechanical properties and structural integrity of the surrounding platform material.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention applies localized material deposition only at the deteriorated zone through laser cladding. The process selectively rebuilds the platform surface where damage exists without subjecting the entire platform to high thermal input. This localized approach maintains the original material properties in unaffected areas while restoring the damaged region.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If laser cladding technology is used to rebuild the damaged areas, then the platform can be restored to original shape, but time consuming milling preparation is required along the whole length of the platform edge

Engineering Contradiction:

Improveplatform restoration precisionVSAvoidpreparation time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies laser cladding only to the specific deteriorated zones rather than preparing and rebuilding the entire platform edge. This partial action approach eliminates the need for extensive milling along the whole platform length, reducing preparation time while maintaining restoration precision in the affected areas only.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The invention performs minimal preliminary preparation of only the deteriorated zones through selective milling or grinding, rather than preparing the entire platform edge in advance. This reduces the time-consuming milling operation to only the necessary areas, enabling faster restoration while achieving the same precision outcomes.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If manual preparation and manual repair are used, then flexibility is increased, but defects like porosity or lack of fusion are frequently created

Engineering Contradiction:

Improverepair flexibilityVSAvoidrepair quality

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces manual preparation and repair operations with automated laser cladding technology. The automated process provides consistent control over deposition parameters, travel speed, and material feed rate, eliminating the human error and inconsistency that lead to porosity and lack of fusion defects while maintaining the ability to adapt to different repair scenarios.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 enhances rebuilding quality by minimizing porosity and cracks, ensuring precise and repeatable repairs with controlled thermal input, improving the integrity and efficiency of the repair process while reducing material removal and costs.

Implementation Method 1

removing part of the outer platform surface comprising the deteriorated zone by means of electro discharging machining technology

Methodology Applied

Scientific EffectElectro discharging machining: Electrical Discharge Machining

Implementation Method 2

rebuilding the removed zone by means of additive manufacturing technology

Methodology Applied

Scientific EffectLaser metal deposition: Laser Beam Welding

Data Source

PatentUS11325211B2Method of restoring a blade or vane platform

Publication Date: 2022.05.10 ANSALDO ENERGIA SPA

AI summary

A method for restoring a blade or vane platform of a gas turbine assembly configured for a power plant by: providing a blade or a vane having a platform with an edge deterioration zone; removing the deterioration zone by electro discharging machining technology; and rebuilding a removed zone by additive manufacturing technology. The removing can be performed to create a recessed plane along a platform edge, the recessed plane being connected to a platform plane by an enter inclined plane and an exit inclined plane arranged opposed along the platform edge.