Dye penetrant testing

Non-Destructive Testing 101

A Resource Guide for Non-Destructive Inspection Methods

Non-Destructive Testing (NDT) is used across industrial environments to provide safe, accurate, and efficient inspection of components and materials. This guide provides an overview of the benefits of non-destructive testing, including industrial and commercial applications for NDT, compatible materials, and the various NDT methods.

What is Non-Destructive Testing?

The term "non-destructive testing" refers to a range of techniques used to evaluate the properties of a material or component without causing any damage. Unlike destructive testing methods, NDT processes allow inspectors to look for cracks, flaws, or other internal defects without the need to break or cut into the object being examined. Benefits of NDT include:

  • Safety: By identifying defects before they cause a failure, NDT can prevent accidents and injuries
  • Cost-Effectiveness: NDT reduces waste by allowing parts to be inspected and used even after testing
  • Quality Control: NDT helps identify defects before a material or component is used in a commercial or industrial setting.
  • Predictive Maintenance: NDT can be used to monitor the condition of in-service equipment and predict potential failures before they occur. This allows for preventive maintenance to be scheduled, reducing downtime and maintenance costs.

Materials Commonly Tested with NDT

NDT methods are used on a wide range of primarily metallic materials, though some testing methods can be used to inspect non-metallic materials. While each method has a different range of compatible materials, some of the most common include:

  • Steel / Steel Alloys
  • Stainless Steel
  • Aluminum
  • Copper
  • Nickel
  • Iron
  • Ceramics
  • Certain plastics

What Industries Utilize Non-Destructive Testing?

NDT inspection services are used in virtually any industrial or commercial application that uses compatible materials and components. Because non-destructive testing provides reliable results without damaging the tested objects, it is widely used in some of the most demanding industries worldwide. Industrial sectors that rely on NDT include:

  • Aerospace: Airplane parts, engine components, and landing gear are inspected for potential defects.
  • Automotive / Transportation: Automotive parts are tested for any flaws or discontinuities.
  • Construction: Used to ensure the integrity of welds and building materials.
  • Manufacturing: Tested for flaws in castings, forgings, and welded components during the production process.
  • Marine: Welds, piping systems, propeller shafts, and other equipment are inspected for any issues.
  • Oil & Gas: Used to examine components in pipelines, pressure vessels, and storage tanks for corrosion and other damage.
  • Power Generation: Nuclear reactor components, turbine parts, and other materials are tested for defects.

Types of Non-Destructive Testing Methods

Visual Inspection

This is the simplest and lowest-cost NDT method. It involves using the naked eye or a magnifying glass to inspect for surface defects. While visual inspections are quicker and lower cost than other methods, it does not provide the in-depth analysis that other NDT methods provide.

Radiographic Inspection

Radiographic Inspection uses X-rays or gamma rays to create an image of the inside of an object, allowing inspectors to identify flaws below the surface. While some testing methods are limited to specific metal families, radiographic inspection can test a broad range of materials, including steel, aluminum, copper, and more. Radiographic testing can also identify several types of defects, including cracks, inclusions, corrosion, and more. This method provides exceptional testing capabilities, though it is often more time-consuming and costly than other NDT processes.

Magnetic Particle Inspection

Magnetic Particle Inspection uses a magnetic field to detect cracks and other defects in ferromagnetic materials. MPI is a reliable, quick, and cost-effective method for identifying surface-level cracks and seams, making it ideal for high-volume applications that do not need to be tested for internal discontinuities.

Liquid Penetrant Testing

Fluorescent Liquid Penetrant Inspection uses a fluorescent liquid that is drawn into cracks and other defects. The tested object is then examined under ultraviolet light, visually revealing flaws. Fluorescent Liquid Penetrant is highly sensitive and can make even minor flaws easily visible to the naked eye. FPI is also compatible with a wide range of metallic and non-metallic materials, including ceramics and plastics.

Eddy Current Inspection

Eddy Current utilizes electromagnetism to detect and characterize flaws in conductive materials. A coil generates a magnetic field that induces electrical currents in a nearby conductor. The flow of these currents is affected by the material's properties and any defects like cracks. By monitoring the coil's response, inspectors can identify areas with disrupted currents, potentially revealing hidden flaws in the metal.

Ultrasonic Testing

Ultrasonic testing uses high-frequency sound waves to detect defects in materials and components. The sound waves reverberate throughout the internal structure of the tested object, creating a pattern. Any cracks or defects within the object disrupt the pattern. Inspectors analyze the pattern, identifying where the disruptions are located. Ultrasonic testing is compatible with both metallic and non-metallic materials.

AMT: Your Source for Industry-Leading Non-Destructive Testing Services

At American Metal Testing, we offer certified non-destructive testing services for commercial and industrial customers nationwide. We specialize in Magnetic Particle Inspection, Fluorescent Penetrant Inspection, and Radiographic Inspection, providing thorough and reliable results with every inspection. Benefits of choosing AMI for your non-destructive testing service needs include:

  • Experienced professionals
  • Industry-leading services
  • Efficient turnaround
  • Unwavering commitment to quality
  • Competitive pricing

Contact Us to Learn How We Can Provide NDT Services for Your Application

Contact AMI to learn how our non-destructive testing services can serve your project. For pricing estimates on your project, request a quote online. American Metal Testing is your trusted source for superior NDT services.