Laser Cleaning Prior to NDT
Laser cleaning is an increasingly popular method for manufacturers prior to conducting Non-Destructive Testing (NDT). The precision that can be applied when removing contaminants makes it an ideal surface preparation technique before inspecting a variety of structures.
What is Non-Destructive Testing?
NDT, also known as NDI (Non-Destructive Investigation) is a type of evaluation method that ensures no damage is done to the structure during the process. It is often used on components that require predictive maintenance and that are in daily service. It is used to pre-empt significant damage from occurring and for manufacturers keen to avoid replacement costs. NDT is important for safety and quality control, as well in an R&D context where companies would like to evaluate the reliability and effectiveness of a product. There are many different types of NDT including dye ultrasonic testing, magnetic particle inspection, and thermographic testing. These procedures are used to inspect welds and the structural integrity of a huge range of manufacturing equipment and constructions.
Why Laser Cleaning Before NDT?
- Precision: Laser systems allow you to target specific areas to clean without damaging the surface profile, which is important for conducting accurate NDT tests. Advanced Optics can enhance this level of specificity in the cleaning process.
- Efficiency: It can be done at speed and over large areas with complex geometries, meaning less downtime for equipment that is NDT tested. Automated laser cleaning systems can deliver fast and accurate decontamination.
- Versatility: Lasers can be configured to clean a variety of different materials such as metals, non-metals, composites, historical artefacts before NDT testing.
Different Types of Non-Destructive Testing Across Industries
Laser cleaning can be used prior to NDT testing across a variety of different industries including in aerospace, automotive, renewables, nuclear, oil and gas, civil engineering, and archaeological restoration. Examples of the different types of NDT testing and their applications are:
- Before ultrasonic testing (including phased array testing) that is used to detect cracks and deformities within welds across aerospace, automotive and civil engineering projects. Laser cleaning allows for hundreds of welds to be prepared in just a matter of hours. Furthermore, existing abrasive methods of removing paint to reveal the weld for testing, can sometimes mask any micro-cracking that may exist in the weld area. A laser will not do this, only help reveal any micro-cracking.
- Ultrasonic testing can also be used to detect defects in aircraft components, marine structures and wind turbine blades. Where laser cleaning allows you to remove rust, oil, grease, and other contaminants without altering the underlying material, other methods can damage the substrate or leave a residue which interferes with the ultrasonic waves and undermines the result.
- For preparing materials before eddy current testing, where defects are uncovered by picking up disruption to a magnetic field. Eddy current testing is useful for detecting small defects near the surface of components. It is used across industries including checking oil and gas pipelines, detecting cracks in railways, evaluating marine hulls and the inspection of nuclear equipment.
- Prior to liquid penetrant testing on non-porous materials. This type of NDT is based around capillary action where liquid fills any surface flaws and unveils these defects to the trained personnel. For this type of method, including dye penetrant testing, laser cleaning systems can be configured to ensure there is a surface roughness on the structure beforehand, which is often useful for this type of test.
- Magnetic particle testing which finds defects in ferromagnetic materials and has many applications including inspecting defence equipment and examining pressure vessels and storage tanks.