Using non-destructive Testing (NDT) have many advantages but only qualified skilled professionals are allowed to conduct the testing. We will differentiate some types of NDT to better understand the concept.
VISUAL INSPECTION AND LIQUID PENETRANT INSPECTION
Visual and liquid penetrant inspection have similarities, these characteristics are:
– Needed to clean surface to inspect thoroughly
– Inexpensive and portable
– Minimum skilled required
– Direct visual detection
– Can be used in metals, ceramics, plastics, rubber, and glass
– Locates surface defects only
– Detects surface cracks or porosity, and lack of bond between joined metals
– Used for aircraft and engine maintenance program
To understand more about the concept, here are their differences:
VISUAL INSPECTION
Visual inspection uses a bright light, boroscope, magnifying glass or a mirror.
Advantage:
- Inspection without disassembly
- Immediate results
- Minimum preparation needed
Disadvantage:
- Scratches maybe misinterpret
LIQUID PENETRANT TEST
Advantage:
- Best to use for nonporous materials
Disadvantages:
- Needed to disassemble a part to be able to inspect it
- Liquid penetrant and remover emulsifier must be applied
- Sensitive to small deburr or random tiny features
- Part preparation needed
- High degree of cleanliness is required
MAGNETIC PARTICLE INSPECTION AND MAGNAGLO INSPECTION
MAGNETIC PARTICLE INSPECTION AND MAGNAGLO INSPECTION are used for:
– For rapid detection of defects near the surface of the ferromagnetic materials
– Not applicable for nonmagnetic materials
– Location, size, and shape of the defects are outlined
– Used on aircraft engine components
– Skills and training are required
– Time consuming for large areas
MAGNAGLO INSPECTION
- Fluorescent particles solution is used
- Black light is needed
- Produces neon-like glow to as a defect indication
- Liquid spray with Magnaglo paste and light oil are needed
- The inspected part should be demagnetized and rinsed with a cleansing solvent
MAGNETIC PARTICLE INSPECTION
- Commonly used for electrically conductive materials
- Magnetic Lines of force pass perpendicular to the defect
- Requires circular and longitudinal magnetization Magnetic flux is induced in many direction Portable and inexpensive