| 摘要 |
1,187,289. Making piezo-electric elements. GENERAL ELECTRIC CO. 10 Oct., 1967 [13 Oct., 1966], No. 46202/67. Headings H1E. [Also in Division C1] An electrostrictive ceramic is heated in a container under reduced pressure, oxygen is admitted to raise the pressure to atmospheric, the ceramic is held at the temperature for a shorter period than the initial heating, and then cooled. Preferred conditions are: temperature 150-200‹ C., initial 4-5 hours and final heat 15-20 minutes. Lead metaniobates and zirconotitanates are specified. The process increases the resistance and is applied before polarization.
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