Non-destructive testing (NDT): identify what type of flaws dye penetrant inspection can reveal Given standard liquid penetrant testing conditions for metals and non-porous materials, determine the class of defects this method is best suited to detect. Choose the most accurate option.
Mechanical Engineering
Engineering Materials
Difficulty: Easy
Choose an option
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ACore defects
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BSurface defects (surface-breaking flaws)
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CSuperficial defects only (cosmetic imperfections unrelated to cracks or porosity)
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DTemporary defects that disappear after cooling
Answer
Correct Answer: Surface defects (surface-breaking flaws)
Explanation
Given
- Dye (liquid) penetrant method for defect detection.
Concept/ApproachLiquid penetrant testing relies on capillary action. A low-viscosity dye seeps into surface-breaking discontinuities and then bleeds out under developer to reveal indications. It cannot detect subsurface flaws because it requires an open-to-surface path.
EliminationCore defects (a) are internal; not detectable unless they break the surface.Superficial (c) is vague and not an NDT category; meaningful targets are cracks, seams, laps, porosity that open to the surface.Temporary defects (d) is not an engineering category.
Final AnswerSurface defects (surface-breaking flaws)