| 摘要 |
<p>The chemical resistance of a gettering device comprising a mixture of barium-aluminium powder and nickel powder compressed in a metal holder is considerably increased by using nickel powder having a specific surface smaller than 0.15 m2 per gram and an average grain size smaller than 80 microns, while the barium aluminium powder has an average grain size smaller than 125 microns. The said gettering device is extremely suitable for use in the manufacture of a colour display tube in which the gettering device is to be placed inside the envelope of the tube before certain parts of said envelope are sealed together at a high temperature.</p> |
