Ferrite Toroid Core: Copper-Zinc Ferrite Fired at 1050 °C, Held at 600 °C in Oxygen (Snoek)

Ferrite is a ceramic magnet: iron oxide combined with other metal oxides, carrying magnetic flux while hardly conducting electricity. Snoek at Philips (US 2,452,531, 1948) made this copper-zinc ferrite ring at a lower heat: technical copper oxide, zinc oxide and iron oxide with 1 % brownstone, fired at 1050 °C, then held 14 hours at 600 °C, all in oxygen. His ring had an initial permeability of 385. The picture: our diagram.

高级

2 days

说明

Mix 20.7 : 31.6 : 47.7 mol + 1 % brownstone

Mix technical copper oxide, zinc oxide and iron oxide in the molecular ratio 20.7 : 31.6 : 47.7 (on the pure oxides) and add 1 % by weight of brownstone (manganese dioxide). Ours, by weight: 13.91 g copper oxide, 21.73 g zinc oxide and 64.36 g ferric oxide per 100 g, plus 1 g brownstone.

此步骤所需材料：

氧化铜13.91 克

氧化锌粉末21.73 克

氧化铁64.36 克

二氧化锰（软锰矿）1 克

所需工具：

等臂天平

防尘口罩

Grind for 3 hours in an iron ball mill

Grind the mixture for 3 hours in a mill with iron balls.

所需工具：

铁球磨机

防尘口罩

Mould a ring at 4 tons per cm²

Mould a ring 3 cm across and 4 × 4 mm in section at 4 tons per square centimetre, with water as the plastifying and binding agent.

所需工具：

液压机

环形压制模

蒸馏水

Fire 1 hour at 1050 °C, hold 14 hours at 600 °C

Sinter the ring in oxygen at 1050 °C for 1 hour, cool it slowly to 600 °C and hold it there for 14 hours, all in oxygen, then let it cool further. Snoek's core had an initial permeability of 385.

所需工具：