Repair & maintenance by Metal Additive Manufacturing process on Titanium alloy parts

Solène Lhabitant,Alain Toufine,Djamel Remache,Guillaume Cohen,Florimont Badouaille

doi:10.1088/1757-899x/1024/1/012022

Abstract

The CRO2 project* deals with both the aircrafts’ parts repair & maintenance and the Additive Manufacturing by metal powder Directed Energy Deposition **.Repairing parts in the aerospace industry is a potential application for additive manufacturing technologies. It’s thus possible to reduce operating losses and to avoid waste of costly and strategic raw materials. CRO2 proposes a pre-industrial development to rebuild lost shapes and functions of Ti64 alloys structures as example in air bled piping. Laser Metal Deposition (DED) process was used for Ti64 parts manufacturing. Tensile and fatigue tests were performed on several samples to characterize the AM material. The mechanical properties of the tested samples are comparable to those of the laminate Ti64 and their microstructure is typical of additive manufacturing. The reliability of the proposed technique, compared to welding repairs’ process, has been successfully demonstrated using aircraft environmental qualification tests at high temperature and pressure carried out on thin representative pipings. (*) CRO2: Cost Repair Overhaul Optimization (**) DED AM: Directed Energy Deposition Additive Manufacturing

Highlights

Titanium alloys are today more and more employed for structural parts in aerospace applications due to their good mechanical properties on severe mechanical and thermal environments, and because they are well compatible with Carbon Fibre Reinforced Plastic structures largely used on new aircrafts’ programs.In aeronautical domain, repairs are a major issue to improve the current way of manufacturing, to avoid waste of costly and strategic raw materials and to reduce operation losses
Samples The microstructure observed on Ti64 samples is fine and lamellar (Figure 3 a-b)
The α and α’ needles phases are detected in β grains. This microstructure is typical of additive manufacturing [3]

Summary

Introduction

Titanium alloys are today more and more employed for structural parts in aerospace applications due to their good mechanical properties on severe mechanical and thermal environments, and because they are well compatible with Carbon Fibre Reinforced Plastic structures largely used on new aircrafts’ programs.In aeronautical domain, repairs are a major issue to improve the current way of manufacturing, to avoid waste of costly and strategic raw materials and to reduce operation losses. Nowadays most of repairs are made by welding or complete replacement of the lost functions or whole parts. These methods have a high energetic impact, weaken locally the parts, make them heavier and modify the paths of mechanical forces. Some studies have been already performed on repair made by Ti64 Additive Manufacturing [1] but only on grooves not on a complete function. Does not completely evaluate the mechanical properties of the deposited materials.

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Results

Conclusion