Damage Tolerance of Thermal Spray Aluminium (TSA) Coatings

In this section

Back to Core Research Programme AMorph – 4D Printing for Field Morphing Structures Automation of Composite and Hybrid Joining Process Coaxial Wire Additive Manufacturing Processes and In-Line Monitoring Tools Development of Coded Excitation Technique for Non-Metallic Pipes Inspection Development of Digital Twin technology as a demonstrator for real-time integrity assessment of crack growth in tensile specimens Development of Friction Stir Welding (FSW) for Hydrogen Fuel Storage Tanks Development of Leak-Before-Break Hydrogen Storage Composite Pressure Vessels With Polymeric Liner Establishing Assessment Methods for Determining Safe Service Limits of High-Temperature Materials in Extreme Environments Fracture toughness in aggressive environments: effect of crack monitoring techniques on test results In-process detection and non-destructive testing of electron beam weld imperfections Internal Bore Coatings for Applications in Corrosion and Hydrogen Environment Joining of Additively Manufactured Materials Long term behaviour of polymeric liner materials/coatings in hydrogen service Techniques for High Temperature Ultrasonic Inspection of Arc Welding Ultimate Leverage Fund

Project Code: 24544

Link to Industrial Member Report

Objectives

To understand the effect of TSA coating damage on the life expectancy of coated offshore structures.

Project Outline

The corrosion testing of coatings which are anodic with respect to the substrate alloy on which they have been applied typically uses test coupons with simulated damage introduced by the removal of 5% of the coating and exposure of the underlying substrate. There are, however, no published data defining the upper limits of acceptable damage or the size and distribution of coating holidays making up a particular percentage. This project will attempt to determine the damage tolerance of TSA coatings on C-steel when immersed in (synthetic) seawater at room temperature. Examples of test coupon total holiday percentage levels and sizes of holidays comprise:

5% (1 x 5%, 5 x 1%)
10% (1 x 10%, 2 x 5%, 5 x 2%, 10 x 1%)
15% (1 x 15%, 3 x 5%, 5 x 3%, 15 x 1%)

Outputs recorded will comprise potential of coated test coupons and linear polarisation resistance data for a period of up to 3 months. Coating corrosion rate will be calculated and correlated with the remaining TSA coating and calcareous compounds deposited from the synthetic seawater test solution.

Relevant Industry Sectors

Technical and Economic Benefits

This will give baseline data for cathodic protection design when using TSA in subsea applications. The application of TSA without any externally applied anodes or impressed current cathodic protection system is likely to reduce costs significantly.