| 摘要 |
PURPOSE:To prevent the expanded thin lead plate from cracking and stress corrosion due to residual internal stress, by forming slits with the irradiation of beams of light or electrons to a thin lead plate prior to expanding. CONSTITUTION:A slitted thin plate is prepared from a rolled thin plate, 1.5mm in thickness, of lead alloy containing, for instance, 2.5% antimony and 0.1% arsenic, by forming staggered slits 2, as 0.5mm wide and 30mm long, with irradiation of laser beams from above the thin plate 1. The thin plate 1 with the slits 2 formed thereon is then expanded to give a grid. The slits 2 thus formed have smooth sides which prevent cracking and stress corrosion due to residual internal stress when the thin plate is expanded. |
