Which of the following materials is most suitable for Liquid Penetrant Testing?

Liquid Penetrant Testing (LPT) is a non-destructive testing method designed to detect surface-breaking defects in various materials. The effectiveness of this method relies heavily on the characteristics of the material being tested.

Metal with surface-breaking defects is the most suitable option for Liquid Penetrant Testing because metals typically have non-porous surfaces that allow the penetrant to enter any cracks or voids readily. This material type has a high level of surface smoothness, which is ideal for ensuring that the penetrant can adequately seep into any discontinuities. Once the penetrant has penetrated the defects, it can be drawn out by a developer, highlighting the location of the defects and allowing for effective visual inspection.

In contrast, the other materials listed pose challenges for LPT. Wood and concrete have porous structures that can absorb the penetrants, leading to ineffective detection of defects. Plastic may also absorb penetrants depending on its type and surface characteristics, but it generally lacks the durability and smoothness that metals provide for effective penetrant testing. Therefore, among the choices available, metal with surface-breaking defects stands out as the most appropriate choice for Liquid Penetrant Testing.