When selecting a powder for magnetic particle medium, what is an important consideration?

When selecting a powder for magnetic particle inspection, providing a high contrast to the surface being tested is crucial. High contrast ensures that the indications produced by any surface or near-surface defects are easily identifiable against the background of the material. This clarity is essential for effective evaluation and assessment of the component being inspected.

A powder that offers high contrast will accentuate cracks, laps, and other discontinuities, making it easier for the inspector to recognize and interpret the results. Factors such as the color and brightness of the magnetic particle medium play a significant role in this aspect. For example, if the component has a dark surface, a lighter powder would provide better visibility of defects, enhancing the overall effectiveness of the inspection process.

While the other considerations could have relevance in specific situations, they do not have the overall importance of achieving high contrast in ensuring effective detection of flaws. Adhering well to the surface can improve inspection quality, but without the visibility provided by high contrast, the detection of defects could still be compromised.