ART
BEAUTY & WELLNESS
CRAFT
CULTURE & HISTORY
ENTERTAINMENT
ENVIRONMENT
FOOD & DRINKS
REVERSE ENGINEERING
SCIENCES
SPORTS
TECHNOLOGY
WEARABLES
Barium-Calcium Ferrite Disc Magnet: 5 % Calcium, Sintered at 1330 °C (Went, Philips 1956, Ex. 18)
A ceramic magnet with a twentieth of the barium replaced by calcium: 0.095 mol barium carbonate, 0.005 mol calcium carbonate and 0.6 mol iron oxide. It is milled, fired in air, milled again, pressed and passed through a 1330 °C furnace in 10 minutes. The X-ray picture showed only the magnetoplumbite phase. Went's rod held 1,680 gauss with a coercive force of 1,110 oersted.
Source: J. J. Went, G. W. van Oosterhout and E. W. Gorter (Philips), US 2,762,777 (1956), Example 18. They sintered rods; discs and the magnetising are ours. Picture: ferrite magnets, Omegatron, Wikimedia Commons, CC BY-SA 3.0.
Advanced
2 days
Instructions
1
1
Weigh barium carbonate, chalk and iron oxide
Weigh barium carbonate, chalk and iron oxide
Weigh 18.74 g barium carbonate (0.095 mol), 0.5 g calcium carbonate (0.005 mol) and 95.55 g ferric oxide (0.6 mol). The patent used analytical-grade carbonates. Barium carbonate is poisonous if swallowed: gloves and a dust respirator.
Materials for this step:
Barium Carbonate (Witherite)18.74 g
Calcium Carbonate - Whiting0.5 g
Ferric Oxide95.55 gTools needed:
Balance Scale
Rubber Gloves
P100 Respirator2
2
Mill 4 hours, dry at 150 °C
Mill 4 hours, dry at 150 °C
Grind with alcohol in a ball mill for 4 hours and dry in air at 150 °C.
Tools needed:
Iron Ball Mill
Ethanol - Lab Grade, 95%
Drying Oven3
3
Presinter in air at 1000 °C for 2 hours
Presinter in air at 1000 °C for 2 hours
Fire the dry powder in air at 1000 °C for 2 hours.
Tools needed:
Muffle Furnace
Crucible with Lid (Porcelain)
Crucible Tongs
Heat-Resistant Gloves4
4
Mill again, dry, press at 1.5 t/cm²
Mill again, dry, press at 1.5 t/cm²
Grind again with alcohol for 4 hours, dry, and press at 1.5 tonnes per cm² (ours: discs instead of rods).
Tools needed:
Iron Ball MillEthanol - Lab Grade, 95%Drying Oven
Hydraulic Press
Disc Pressing Die5
5
Pass through a 1330 °C zone in 10 minutes
Pass through a 1330 °C zone in 10 minutes
Sinter at 1330 °C by passing the pieces through a 10 cm hot zone at 10 mm per minute: 10 minutes in the heat.
Tools needed:
Tube FurnaceHeat-Resistant Gloves6
6
Magnetise the discs
Magnetise the discs
The patent gives no magnetising method. Ours: lay a disc with its faces against the poles of a strong electromagnet, switch the current on, then off. Find which face is north with a compass.
Tools needed:
Electromagnet
CompassMaterials
3- 18.74 gPlaceholder
- Placeholder
- 95.55 gPlaceholder
Tools Required
15- Placeholder
- 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.