Titanium Blade Armor via Low-Temperature Slurry Firing

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Solution Overview

Problem

Existing methods for applying armor to turbomachine rotor blades, particularly those made of titanium, are complex and unsuitable due to the risk of titanium fire ignition from heat input during friction, and lack adequate wear resistance and rubbing properties.

Innovation Solution

A method involving a slurry of metallic powder and binder, comprising elements like iron, nickel, or cobalt, applied to titanium blades, which is dried and then fired to create a hardfacing with ceramic components, providing armor that reduces the risk of titanium fire ignition and improves wear resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ceramic materials (aluminum oxide, zirconium oxide) or cubic boron nitride are applied by thermal spray, galvanic deposition, or soldering, then wear resistance and heat resistance are improved, but the process complexity increases and titanium fire ignition risk occurs due to high heat input

Engineering Contradiction:
Improvewear resistanceVSAvoidprocess complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention changes the application parameters by using a slurry composition with metallic powder (Fe, Ni, Co, Cr, Al) and organic binder that can be applied at room temperature or low temperature, then fired at relatively low temperatures (900-1100°C). This avoids the high heat input of conventional thermal spray while achieving comparable wear resistance through the formation of a protective oxide layer during firing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite slurry material combining metallic powder (Fe, Ni, Co, Cr, Al) with organic binder (polysiloxane or polysilazane). This composite approach allows the armor layer to form a protective ceramic-metal composite structure after firing, where the metallic components provide toughness and the ceramic oxides provide wear resistance, while the organic binder enables low-temperature processing.

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional armor materials are applied to titanium blades, then protection against wear and heat is improved, but titanium fire ignition risk increases due to high heat input from friction and application processes

Engineering Contradiction:
Improveprotection against wear and heatVSAvoidtitanium fire ignition risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention converts the potential harm of heat input into a benefit by using controlled low-temperature firing (900-1100°C) that forms a protective oxide layer on the armor material and the titanium substrate. This controlled oxidation during firing creates a stable, protective interface that actually reduces the risk of titanium fire during operation, transforming the heat sensitivity into a protective mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The organic binder (polysiloxane or polysilazane) acts as an intermediary that enables low-temperature application and firing of the armor slurry. This binder decomposes controllably during firing, facilitating the formation of a protective ceramic-metal composite structure without requiring high heat input that would ignite titanium, thus mediating between the armor material and the titanium substrate.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If complex armor application methods are used, then wear resistance is improved, but manufacturing simplicity and cost-effectiveness deteriorate

Engineering Contradiction:
Improvewear resistanceVSAvoidmanufacturing simplicity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention replaces complex mechanical application methods (thermal spray, galvanic deposition, soldering) with a chemical/colloidal approach using a slurry that can be applied by simple coating methods. The slurry contains metallic powder and organic binder that form a adherent coating upon firing, substituting complex mechanical processes with a simpler chemical deposition and firing process.

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

Solution Approach 2:

The invention changes the manufacturing parameters by using a slurry composition and firing process that simplifies production. The slurry can be applied at room temperature or low temperature, and firing at 900-1100°C is simpler than thermal spray equipment requirements. This parameter change makes the process more manufacturable while maintaining wear resistance through the formation of a protective oxide layer.

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 enables simple, effective armor application on titanium blades with enhanced wear resistance and rubbing properties, reducing the risk of titanium fire ignition and improving adhesion through a running-in process that forms a protective reaction zone.

Implementation Method 1

After applying the slip, the slip can be dried.

Methodology Applied
Scientific EffectDrying: Evaporation

Implementation Method 2

After drying or immediately after application without drying, the slip can be fired so that the slip becomes armor-plated.

Methodology Applied
Scientific EffectFiring: Sintering

Implementation Method 3

The binder and the metallic powder can each make up about half the volume of the slurry... The slip can then be burned by locally heating the blade in the region of the applied slip or by completely heating the blade.

Methodology Applied
Scientific EffectPyrolysis: Pyrolysis

Implementation Method 4

the heat introduced into the blade as a result Reaction zone between the armor and the titanium - material can form

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 5

heat input due to friction of the blade tips on the Housing seal

Methodology Applied
Scientific EffectHeat input: Heating

Data Source

PatentEP2842662B1Armour plating for a blade tip for titanium blades
Publication Date: 2020.08.05 MTU AERO ENGINES GMBH
  • EP2842662B1 patent drawingFigure 1~2

AI summary

The present invention relates to a method for producing a blade armor of a turbomachine blade, wherein the blade (1) is at least partially formed from a titanium material, and the method comprises the following steps: providing a blade with the titanium material; providing a slurry comprising a metallic powder and a binder, wherein the metallic powder is formed from a material comprising M, Cr, and Al, where M is at least one element selected from the group comprising Fe, Ni, and Co; applying the slurry to the titanium material in at least a partial region of the blade; drying and/or firing the slurry to form an armor (4). The present invention further relates to a turbomachine blade with a blade armor produced according to the method.