Laser graving of characters on ceramic substrates and change in visibility in corrosive environments

Laser graving of lines and characters was studied on alumina (Al₂O₃), zirconia (ZrO₂) and silicon carbide (SiC) substrates to apply it to prolonged record conservation media. Graved lines were not clear on alumina and zirconia substrates, whereas on a SiC board, they were clearly identified by optical observation. Characters were graved on SiC substrates, and the stability of their visibility was investigated by thermal and chemical corrosion examinations. In high-temperature corrosion examination of the graved SiC, the visibility of characters decreased after 1 week, but no more changes were subsequently observed. In chemical corrosion examination, the visibility was remarkably degraded in concentrated alkaline solution, but not changed in acid and diluted alkaline solutions. (author)