| 摘要 |
1,267,216. Capacitors &c. INTERNATIONAL BUSINESS MACHINES CORP. 28 July, 1969 [5 Aug., 1968], No. 37767/69. Heading HlH. In a process for mass-producing linear ferrite cores which includes steps of batch pressing and sintering raw powdered ferrite, a batch of cores is mechanically agitated at ultrasonic frequency, in a medium in which the cores are permitted to abrasively collide with each other at random, for a time sufficient to reduce magnetostrictive ringing as ascertained from measurements made on a sampling of the cores prior to agitation. The medium may be an alcoholic suspension of alumina particles contained in a beaker placed in an ultrasonically vibrating tank. The treated cores are removed from the medium magnetically, and air-dried. Preparation of cores from ZnO, NiCO 3 and Fe 2 O 3 is described, the process involving granulating ferrite powder and polyvinyl alcohol binder, moulding the granules, and sintering the resulting cores. Cores of Mn 0 . 8 Zn 0 . 2 Fe 2 O 3 are also specified. |
