Turbine Airfoil Tip Build Surface for Ceramic-Supported DMLM

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Solution Overview

Problem

Current methods for manufacturing and repairing turbine blades and vanes are time-consuming and costly, particularly at the tips, which are prone to damage and require expensive replacement, and often necessitate the use of new materials, whereas existing materials in airfoil manufacturing facilities are not fully utilized.

Innovation Solution

The method involves using a ceramic casting mold with an internal core and external shell as a support structure for direct metal laser melting (DMLM) to additively manufacture turbine blade tips, leveraging the ceramic's high strength and inert properties to create a cost-effective and time-efficient process that reuses existing materials and maintains the microstructure of the airfoil.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional welding methods are used to join turbine blade tips, then the blade can be repaired or extended, but the process is time-consuming and costly due to the complexity of superalloy welding

Engineering Contradiction:
Improveproduction timeVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent replaces traditional mechanical welding processes with direct metal laser melting (DMLM) additive manufacturing. Instead of using welding equipment and procedures to join blade tips, the invention uses laser-based additive manufacturing to directly deposit and fuse metal powder onto the blade tip area, eliminating the complex welding operations and significantly reducing production time and cost.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If new materials are used for manufacturing turbine blade tips, then the microstructure and quality can be maintained, but the cost increases and existing materials in facilities are not utilized

Engineering Contradiction:
Improvemicrostructure qualityVSAvoidmaterial cost
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the manufacturing parameters and process method rather than changing the material itself. By using DMLM additive manufacturing with existing superalloy powders, the invention maintains the same material composition and microstructure quality as traditional casting methods while eliminating the need for expensive new materials. The process parameters (laser power, scan speed, layer thickness) are optimized to achieve the desired microstructure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention enables the manufacturing facility to use its existing superalloy powder inventory for blade tip production through DMLM, rather than requiring procurement of new specialized materials. The additive manufacturing process allows the facility to self-sufficiently produce blade tips using materials already available in their supply chain, reducing material costs and waste.

Inventive Principle:
Principle #25Self-service

3Productivity

If ceramic cores are removed from turbine blades after casting, then cooling chambers can be formed, but the process requires additional steps and time

Engineering Contradiction:
Improveproduction efficiencyVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent incorporates the ceramic core removal step into the overall process planning from the beginning. The ceramic core is designed with specific features (such as soluble materials or removable structures) that allow for efficient removal after casting. The process sequence is optimized so that core removal is performed at the most convenient time, and the additive manufacturing of blade tips is coordinated with this timing to minimize total production time and complexity.

Inventive Principle:
Principle #10Preliminary action

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 reduces production time and costs by utilizing existing materials and equipment, ensuring the quality of the additively manufactured tip matches the airfoil's microstructure, while allowing for efficient removal of the ceramic core post-manufacturing, thus extending the life of turbine components.

Implementation Method 1

direct metal laser melting (DMLM) to additively manufacture turbine blade tips

Methodology Applied
Scientific EffectLaser melting: Laser

Implementation Method 2

molten alloy powder is deposited on the tip plate 50 in one or more passes

Methodology Applied
Scientific EffectLaser fusion: Laser Beam Welding

Implementation Method 3

leveraging the ceramic's high strength and inert properties to create a cost-effective and time-efficient process

Methodology Applied
Scientific EffectCeramic strength: Refractory Material

Data Source

PatentEP3585556B1Method of manufacturing turbine airfoil and tip component thereof
Publication Date: 2023.10.04 GENERAL ELECTRIC CO
  • EP3585556B1 patent drawingFigure 1
  • EP3585556B1 patent drawingFigure 2A~2B
  • EP3585556B1 patent drawingFigure 3A~3C

AI summary

Methods of manufacturing or repairing a turbine blade or vane are described. The airfoil portions of these turbine components are typically manufactured by casting in a ceramic mold, and a surface made up of the cast airfoil and at the least the ceramic core serves as a build surface for a subsequent process of additively manufacturing the tip portions. The build surface is created by removing a top portion of the airfoil and the core, or by placing an ultra-thin shim on top of the airfoil and the core. The overhang projected by the shim is subsequently removed. These methods are not limited to turbine engine applications, but can be applied to any metallic object that can benefit from casting and additive manufacturing processes. The present disclosure also relates to finished and intermediate products prepared by these methods.