Testing materials, components, devices and equipment for flaws and defects is a critical part of product safety. A process known as non-destructive testing determines these items’ durability and potential failure. Industries like automotive, oil and gas, construction, aerospace and aviation must use NDT to verify their assets’ quality and safety without causing damage.
Evaluating these structures also determines whether the final product will operate according to its design specifications. For instance, defense and commercial aircraft sectors can test cartridge-actuated devices and propellant-actuated devices to ensure they meet rigorous standards.
Non-Destructive Testing vs. Destructive Testing
The difference between non-destructive testing and destructive testing is whether the process damages the specimen. As the term suggests, non-destructive testing leaves components intact. After the test, they can operate as usual unless they are defective. Alternatively, tests that harm products are destructive.
Another notable distinction is that NDT and DT are generally for different applications. NDT is excellent for:
- Evaluating failure analysis
- Identifying defects and discontinuities in materials
- Spotting early signs of equipment deterioration
- Preventing equipment failure
- Determining satisfactory function in an existing product
- Assessing the extent of wear and tear
DT is typically for:
- Identifying chemical and physical properties
- Assisting in the design phase
- Determining a product’s operational limits
- Checking item quality before mass production
NDT in the Aviation Industry
Non-destructive testing is only one form of quality assurance and preventive maintenance in the aviation industry. NDT is critical for private, military defense and commercial aircraft because it offers insights into the structural health of aircraft and their components without causing damage.
Various NDT methods can quickly detect and analyze potential faults, enabling prompt interventions that keep aircraft parts safe and in working order. NDT is critical to aviation maintenance because it allows companies to better understand and comply with industry regulations, codes and standards, including those set by:
Non-Destructive Testing Methods and Techniques
Non-destructive testing methods allow inspectors to reach detailed conclusions in various ways. Here are some examples of common NDT methods that military, commercial and private aircraft companies use.
1. Visual Testing
Visual testing, also known as visual inspection, is a simple NDT method that involves the observation of the test subject’s surface for damage or discontinuities, such as:
- Cracks
- Welding defects
- Deformations
- Corrosion
- Part misalignment
In this method, an inspector visually examines the product or equipment to locate defects or a missing step during manufacturing before conducting further NDT.
Visual inspection is integral to routine maintenance in almost ever processes or while a product is in service. Some inspectors may use artificial intelligence, remote drones or machine learning algorithms to assess hazardous components and access hard-to-reach places.
2. Electrical Resistance Testing
Electrical resistance testing is a form of NDT that uses various instruments and probes to measure the extent of total metal loss for any metallic equipment or object. ER can also test an object’s ability to resist electrical currents. For instance, inspectors can use ER tests to determine if a resistor works correctly and identify metal loss from corrosion or erosion.
Though ER is a highly universal form of testing for many applications, it’s often best for corrosive environments that contain poor or non-continuous electrolytes like gases, soils and vapors. During ER testing, a current flows through the tested object when connected to a probe. Inspectors measure the amount of voltage to determine the object’s or resistor’s electrical resistance.
3. Helium Leak Testing
Leak testing is an NDT method used to determine the compliance, integrity and safety of pressurized and sealed systems, such as:
- Chemical basins
- Gas tanks
- Refrigeration systems
When conducting LT, inspectors often use a pressure gauge, electronic listening devices or soap-bubble tests to take measurements that detect leaks, cracks and other defects. A form of LT called mass spectrometer testing involves infusing a test chamber with helium or a blend of helium and air. Then, inspectors can use mass spectrometer equipment to detect gas leaks by ionizing the helium.
4. Radiographic Testing
Radiographic testing, or industrial radiography, is another typical NDT method for testing internal structures. This technique uses X-rays or gamma rays to obtain detailed insights of dense materials like aircraft components. RT can detect flaws in machinery and welding, making it critical for aviation safety.
During testing, gamma radiation passes through the test object. Darker areas on the recording medium indicate higher radiation levels, indicating cracks or gaps. X-rays are excellent for testing thinner materials, while gamma rays are ideal for thicker materials. The NDT technique can also identify:
- Excessive reinforcement
- Surface and subsurface discontinuities
- Undercut
- Inadequate joint penetration
- Volumetric defects
- Insufficient fusion
- Porosity
- Excess root penetration
RT requires little surface penetration and is a convenient testing method for elevated and field environments.
Enhance Equipment Safety and Reliability With AETC
Non-destructive testing is an umbrella term for various testing methods that spot defects and enable improved product quality. At AETC, NDT is only one of the many rigorous methods we use during CAD/PAD production.
For over 40 years in the industry, we’ve designed and improved innovative solutions that meet our customers’ unique needs in the aviation, space, defense and oil and gas industries, offering tailored, reliable products from cartridges to pyrotechnic initiators to detonators. Contact us today to learn more.
