Improving and Industrialising Cold Spray Repair
Status: Proposal
Date Announced: April, 2023
Project reference: PROP310955
Summary
Current Repair Technology
Many components are retired from service due to relatively minor damage resulting from corrosion, wear or foreign object damage. Implementing a reliable, repeatable, cost effective repair strategy putting components back into service could result in significant cost savings by eliminating the need to install new parts, thereby reducing the need for holding stock or taking platforms out of service while new components are manufactured. Repair also reduces the embodied energy and CO2 emissions associated with replacing parts with newly build.
Current fusion/weld-based repairs of metallic components add significant heat input into the material, which alters the underlying microstructure, often leading to unacceptable degradation to mechanical properties. Weld-based repairs can also be challenging for highly oxygen sensitive materials, such as aluminium, magnesium and titanium, and require inert environments which may be impractical. Weld-based repairs also result in residual stresses, which can lead to unacceptable part distortions or that degrade the fatigue life of the part.
Parts can also be repaired using polymer fillers (such as epoxy), which only provides limited mechanical properties and restrict the lifetime of the repair. The upper temperature limit of such repair is also significantly constrained.
Cold Spray Repair
Cold spray is a solid-state deposition technology that results in little to no heat input to the component, thereby retaining the original mechanical properties in the parent material. Oxygen-sensitive materials can be processed without the need for inert conditions and the resulting deposition generally results in compressive residual stresses that do not degrade the fatigue life of the component. Process variants exist that mean the process is highly flexible, allowing a range of different materials to be deposited at high rate across a range of cost-quality measures.
Objectives
This Joint Industry Project aims to support TWI members in implementing cold spray as a repair technology by:
- Developing new approaches to cold spray to improve deposit performance and allow a broader range of materials to be sprayed;
- Generating independent data on the performance of cold spray deposits to aid users in the development of safety cases and future certification;
- Developing guidelines to support the implementation of cold spray, allowing sponsors to better understand potential benefits, limitations and costs.
Benefits
By participating in this project, TWI members will have access to:
- The latest techniques for improving the properties of cold spray deposits, increasing the number of potential candidate repairs that could be considered and/or increasing the performance and lifetime of repaired components;
- Tools to monitor and control the cold spray process, allowing greater confidence in the quality and repeatability of repairs that can be achieved;
- Independent datasets on the performance of cold spray repairs that allow informed decision making and support future verification/qualification/certification activities for potential cold spray repairs;
- Repair frameworks, guideline documents, proven QA and NDE techniques that reduce the cost burden and accelerate the ability to adopt cold spray within a commercial environment.
If you are interested in finding out more, see the PDF download. If you would like to join this JIP, please contact us.