Table 4.
Precrack inspection procedures
| Lab | Procedure | |
|---|---|---|
| ZAC | Silicon nitride | |
| NIST | Green felt-tip pen | (Fluorescent dye penetrant-unsuccessful) Low-angle incident lighting |
| USA lab 2 | Commercial blue dye penetrant | Commercial blue dye penetrant |
| USA lab 3 | Felt-tip pen | Blue food coloring, applied under load |
| USA lab 4 | (Red dye penetrant unsuccessful) | (Red dye penetrant unsuccessful) |
| Low-angle incident lighting | Low-angle incident lighting | |
| USA lab 5 | Acetone and dye,fractographic inspection | Acetone and dye, fractographic inspection |