Laser Repair of Titanium Blisk Blades

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional build-up welding techniques, such as TIG and microplasma welding, face challenges when repairing titanium alloy blisks due to the formation of volume defects like micropores and an extended heat-affected zone, which weaken the mechanical properties and are difficult to control, especially in complex three-dimensional designs like compressor blades in aeronautical turbomachines.

Innovation Solution

The method employs laser build-up welding with a predefined set of operating parameters validated through test pieces, ensuring minimal defects and reliable repair by maintaining consistent heat influx and preventing outgassing, using a laser beam to deposit filler material in the form of powder or wire, with parameters checked to ensure quality and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional TIG build-up welding is used to repair titanium alloy blisks, then the repair can be performed with widely available equipment, but volume defects like micropores and an extended heat-affected zone form, weakening mechanical properties by up to 80%

Engineering Contradiction:

Improveavailability of welding equipmentVSAvoidmechanical properties of repaired zone

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the fundamental welding parameters by switching from conventional TIG welding to laser build-up welding. This parameter change enables precise control of heat input, resulting in minimal heat-affected zone and no volume defects, thereby restoring mechanical properties while maintaining repair feasibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the conventional TIG welding mechanism with laser welding technology. This substitution eliminates the need for manual electrode manipulation and provides automated, precise material deposition with controlled thermal input, preventing defect formation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If microplasma build-up welding is used to repair titanium alloy blisks, then the heat-affected zone is reduced compared to TIG welding, but the method requires periodic inspection and maintenance of equipment to prevent parameter drift

Engineering Contradiction:

Improveheat-affected zone sizeVSAvoidequipment inspection and maintenance requirements

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The laser build-up welding system incorporates automated monitoring and control mechanisms that self-regulate welding parameters throughout the repair process, eliminating the need for periodic manual inspection and maintenance while maintaining consistent quality

Inventive Principle:

Principle #25Self-service

3Ease of repair

If build-up welding is used to repair damaged zones on blisks, then the removed material can be replaced, but the welding process creates volume defects that are difficult to detect and generate significant mechanical weakening

Engineering Contradiction:

Improveability to replace removed materialVSAvoiddetectability of volume defects

Core Design Contradiction:

Ease of repairVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces conventional welding with laser build-up welding, which uses a focused laser beam to melt and deposit material with precise control. This substitution eliminates the arc-related instability and material entrapment that cause micropores and blisters in conventional welding

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the thermal input parameters by using a highly concentrated, controllable laser beam instead of a diffuse arc. This enables precise control of melting and solidification rates, preventing gas entrapment and defect formation during material deposition

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

This approach minimizes defects in the weld zone, enhances the reliability and repeatability of the repair process, and allows for effective repair of complex components like blisks with reduced mechanical weakening, particularly suitable for titanium alloys like Ti17, by maintaining the structural integrity and aerodynamic performance.

Implementation Method 1

the heating is performed by a laser beam

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

build-up welding technique by application of a laser beam... deposit filler material

Methodology Applied

Scientific EffectMelting: Melting

Data Source

PatentUS8049132B2Method of repairing a blisk and test pieces by welding

Publication Date: 2011.11.01 SAFRAN AIRCRAFT ENGINES SAS

AI summary

A method of repairing a turbomachine blisk having at least one damaged zone by build-up of metal in the damaged zone using a laser build-up welding machine is disclosed. The method includes preparing the damaged zone by machining the damaged zone to obtain a zone of defined profile to be repaired, build-up welding of a start-of-run test piece that includes the defined profile using the laser build-up welding machine, checking geometric and metallurgical quality of the test piece, and build-up welding the zone to be repaired of the blisk using the laser build-up welding machine.