Titanium Fire-Resistant Shell Coating With Gradient Interface Control

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Solution Overview

Problem

Current methods for manufacturing titanium alloy parts, such as high-pressure compressor casings, face challenges in controlling the interface position and thickness ratio between titanium and other alloys, leading to low shear resistance and high costs due to complex processes and significant differences in expansion coefficients.

Innovation Solution

A manufacturing process involving additive manufacturing of a titanium fire-resistant covering layer on a titanium-based shell, followed by a heat treatment between 200°C and 1000°C, with optional intermediate layers forming a composition gradient to enhance adhesion and mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional methods (hot rolling, hydraulic plating, sockets) are used to fix another alloy part to the titanium part, then fire resistance is improved, but the shear strength between the two materials deteriorates due to large differences in expansion coefficients

Engineering Contradiction:
Improvefire resistanceVSAvoidshear strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent merges the titanium part and the fire-resistant alloy part into a single monolithic component manufactured by additive manufacturing. The gradient structure creates a continuous transition zone where material composition gradually changes from pure titanium to fire-resistant alloy, eliminating the sharp interface and associated weak bonds. This unified structure maintains fire resistance while achieving superior shear strength through continuous material gradation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs composite materials with a gradient composition, transitioning from titanium-based material to fire-resistant alloy. This composite structure with varying material properties through the thickness allows simultaneous optimization of fire resistance (provided by the alloy layer) and shear strength (enhanced by the gradient transition zone that accommodates thermal expansion differences).

Inventive Principle:
Principle #40Composite materials

2Reliability

If traditional assembly methods are used to fix another alloy part to the titanium part, then fire resistance is improved, but manufacturing precision deteriorates due to difficulty in controlling interface position and thickness ratio

Engineering Contradiction:
Improvefire resistanceVSAvoidinterface position control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

By merging the manufacturing process into a single additive manufacturing operation, the patent eliminates the need for separate assembly steps. The interface position and thickness ratio are controlled by digital design parameters and built-in-layer deposition precision, achieving manufacturing precision unattainable through traditional assembly methods which rely on mechanical tolerances and manual positioning.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes parameter changes in material composition through the gradient structure, where the proportion of fire-resistant alloy gradually increases from the titanium side to the alloy side. This compositional parameter gradient, controlled during additive manufacturing, enables precise control of interface characteristics and thickness ratios that cannot be achieved through traditional assembly tolerances.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If traditional assembly methods are used to fix another alloy part to the titanium part, then fire resistance is improved, but device complexity increases due to multiple processing steps and machining requirements

Engineering Contradiction:
Improvefire resistanceVSAvoidnumber of processing steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions (fire protection, structural integrity, thermal management) and manufacturing steps (part fabrication, interface creation, heat treatment) into a single additive manufacturing process followed by one heat treatment step. This consolidation reduces device complexity from multiple assembly and machining operations to a streamlined process of additive manufacturing plus heat treatment, while maintaining fire resistance through the gradient structure.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If another alloy part is fixed to the titanium part using traditional methods, then fire resistance is improved, but cost increases due to complex processes and machining requirements

Engineering Contradiction:
Improvefire resistanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By merging the titanium part and fire-resistant alloy part into a single additive manufacturing process, the patent eliminates costs associated with separate part fabrication, assembly operations, and post-assembly machining. The gradient structure is built directly during manufacturing without requiring complex assembly fixtures or multiple machining steps, significantly reducing overall manufacturing cost while maintaining fire resistance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces traditional mechanical assembly methods (hot rolling, hydraulic plating, socket connections) with additive manufacturing technology. This substitution eliminates the need for complex mechanical assembly equipment, assembly tooling, and subsequent machining operations, thereby reducing manufacturing cost while achieving the same fire resistance function through the gradient structure.

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 process optimizes the interface between titanium and fire-resistant materials, improving shear resistance and maintaining mechanical strength while reducing costs by allowing for precise control of layer thickness and adhesion, thus addressing the limitations of existing methods.

Implementation Method 1

a heat treatment of the metal part is carried out at a temperature between 200°C and 1000°C

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

a covering layer made of a fire-resistant titanium material is produced by additive manufacturing on the shell

Methodology Applied
Scientific EffectAdditive manufacturing: 3D Printing

Data Source

PatentEP4127265B1Method for manufacturing a titanium fire-resistant metal component by additive manufacturing
Publication Date: 2024.11.27 SAFRAN AIRCRAFT ENGINES SAS
  • EP4127265B1 patent drawingFigure 1

AI summary

Method for manufacturing a metal component (1), characterized in that it comprises the following steps: a shell (2) made of a titanium-based material is provided, the shell (2) having a first surface (3) and a second surface (4) remote from the first surface (3); a covering layer (5) made of a titanium fire-resistant material is produced by additive manufacturing on the shell (2) such that said covering layer (5) at least partially covers the first surface (3) and/or the second surface (4); and, after the additive manufacturing step, the metal component (1) is heat treated at a temperature of between 200°C and 1000°C.