What is NDT inspection?

NDT testing (Nondestructive Testing, NDT) is a technology for evaluating the performance of materials, components or structures, aiming to find defects without damaging the test object. It uses the changes in physical quantities such as heat, sound, light, electricity, and magnetism caused by abnormal internal structure or defects of the material to detect internal and surface defects of various engineering materials, parts, structural parts, etc. through specific detection methods.

Basic principles of NDT testing
The basic principle of NDT testing is to use the changes in physical quantities such as heat, sound, light, electricity, and magnetism caused by abnormal internal structure or defects of the material. These changes can be detected and evaluated by different detection technologies to understand the properties, state or internal structure of the material.

Application scope of NDT testing
NDT testing is widely used in the detection of metal materials, non-metallic materials, composite materials and their products, as well as some electronic components. It can not only be used for quality control in industrial manufacturing, but also for fault diagnosis during maintenance and overhaul.

Common NDT testing methods
Common NDT testing methods include:

1. Visual inspection: direct or remote observation through optical devices such as magnifiers, borescopes, cameras, etc.

2. Radiographic testing (NT): Volumetric testing using X-rays, neutrons or gamma radiation.

3. Ultrasonic testing (UT): Using ultrasound to evaluate the internal structure of a material.

4. Liquid penetrant testing (PT): Using dyes or fluorescent liquids to detect surface defects.

5. Magnetic particle inspection: Detecting surface or near-surface defects by magnetizing parts and observing the aggregation of magnetic particles.

Development trend of NDT testing
With the advancement of technology, NDT testing is becoming more and more widely used in the industry, and new testing methods and equipment are constantly emerging to improve the accuracy and efficiency of testing.