ART
BEAUTY & WELLNESS
CRAFT
CULTURE & HISTORY
ENTERTAINMENT
ENVIRONMENT
FOOD & DRINKS
REVERSE ENGINEERING
SCIENCES
SPORTS
TECHNOLOGY
WEARABLES
Oriented Barium Ferrite Disc Magnet: Water Instead of a Binder (Gorter, Philips 1956, Ex. 5)
A ceramic magnet from pre-fired barium ferrite powder stirred into water, oriented in a magnetic field in the die, moulded into blocks and fired as in Example 4. In the principal direction it held 2,870 gauss with a coercive force of 1,610 oersted and a (BH)max of 1.57 × 10⁶; at right angles 1,625 gauss.
Source: E. W. Gorter, G. W. Rathenau and A. L. Stuyts (Philips), US 2,762,778 (1956), Example 5. They made blocks; disc size is ours. Picture: ferrite magnets, Omegatron, Wikimedia Commons, CC BY-SA 3.0.
Advanced
3 days
Instructions
1
1
Weigh barium carbonate and iron oxide
Weigh barium carbonate and iron oxide
Weigh 450 g barium carbonate and 2000 g ferric oxide. Barium carbonate is poisonous if swallowed: gloves and a dust respirator.
Materials for this step:
Barium Carbonate (Witherite)450 g
Ferric Oxide2000 gTools needed:
Balance Scale
Rubber Gloves
P100 Respirator2
2
Mill 20 hours under alcohol, dry
Mill 20 hours under alcohol, dry
Grind the mixture in a ball mill under alcohol for 20 hours, then dry it.
Tools needed:
Iron Ball Mill
Ethanol - Lab Grade, 95%
Drying Oven3
3
Pre-fire: through a 1100 °C zone in 10 minutes
Pre-fire: through a 1100 °C zone in 10 minutes
Pass the dry powder at 20 mm per minute through an electric furnace with a 20 cm hot zone at 1100 °C, in air: 10 minutes in the heat. Let it cool.
Tools needed:
Tube Furnace
Crucible with Lid (Porcelain)
Heat-Resistant Gloves4
4
Grind 12 hours with alcohol, dry
Grind 12 hours with alcohol, dry
Pulverise the pre-fired material in a ball mill with alcohol for 12 hours, then dry it. This is the pre-fired powder.
Tools needed:
Iron Ball MillEthanol - Lab Grade, 95%Drying Oven5
5
Stir into water
Stir into water
Stir the pre-fired powder with water, 2 cc of water per gram of powder.
Tools needed:
Distilled Water6
6
Orient in a first field and mould
Orient in a first field and mould
Put the suspension in a moulding die, apply a first magnetic field and mould it into blocks. The patent does not give this field's strength.
Tools needed:
Disc Pressing Die
Electromagnet
Hydraulic Press7
7
Heat to 500 °C in a 2000 oersted field
Heat to 500 °C in a 2000 oersted field
Put the block in an electric furnace between the magnet's poles. With a second field of 2000 oersted along the first field's direction, heat to 500 °C, which burns off the rest of the binder. Then switch the field off.
Tools needed:
Tube FurnaceElectromagnetHeat-Resistant Gloves8
8
Sinter: through a 1280 °C zone in 5 minutes
Sinter: through a 1280 °C zone in 5 minutes
Pass the block at 20 mm per minute through an electric furnace in air at 1280 °C with a 10 cm hot zone: about 5 minutes in the heat.
Tools needed:
Tube FurnaceHeat-Resistant Gloves9
9
Magnetise in the principal direction
Magnetise in the principal direction
Magnetise the block along the direction of the first field, the principal direction. The patent magnetises it in a field in that direction; ours: an electromagnet. Find the north face with a compass.
Tools needed:
Electromagnet
CompassMaterials
2- Placeholder
- 2000 gPlaceholder
Tools Required
14- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
- Placeholder
This blueprint makes
Related Blueprints
These blueprints share knowledge with this one — techniques, materials, or principles that connect them in the learning graph.
CC0 Public Domain
This blueprint is released under CC0. You are free to copy, modify, distribute, and use this work for any purpose, without asking permission.
Support the Maker by purchasing products through their Blueprint where they earn a Maker Commission set by Vendors, or create a new iteration of this Blueprint and include it as a connection in your own Blueprint to share revenue.