ART
BEAUTY & WELLNESS
CRAFT
CULTURE & HISTORY
ENTERTAINMENT
ENVIRONMENT
FOOD & DRINKS
REVERSE ENGINEERING
SCIENCES
SPORTS
TECHNOLOGY
WEARABLES
Strontium Ferrite Disc Magnet: Presintered, 4 Minutes at 1150 °C (Went, Philips 1956, Ex. 25)
A strontium ferrite with more strontium: 0.4 mol strontium carbonate to 0.8 mol iron oxide, milled, presintered at 1000 °C, milled again, pressed and passed through a 1150 °C furnace in 4 minutes. Went's rod held 1,200 gauss with a coercive force of 3,710 oersted.
Source: J. J. Went, G. W. van Oosterhout and E. W. Gorter (Philips), US 2,762,777 (1956), Example 25. 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
Dry the strontium carbonate and weigh
Dry the strontium carbonate and weigh
Dry the strontium carbonate at 100 °C. Weigh 59.05 g of it (0.4 mol) and 127.5 g ferric oxide (0.8 mol).
Materials for this step:
Strontium Carbonate59.05 g
Ferric Oxide127.5 gTools needed:
Drying Oven
Balance Scale
P100 Respirator2
2
Mill 7 hours, dry at 110 °C
Mill 7 hours, dry at 110 °C
Grind with alcohol in a ball mill for 7 hours and dry at 110 °C.
Tools needed:
Iron Ball Mill
Ethanol - Lab Grade, 95%Drying Oven3
3
Presinter in air at 1000 °C for 4 hours
Presinter in air at 1000 °C for 4 hours
Fire in air at 1000 °C for 4 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 7 hours with alcohol, dry at 110 °C and press at 1.5 tonnes per cm² (ours: discs).
Tools needed:
Iron Ball MillEthanol - Lab Grade, 95%Drying Oven
Hydraulic Press
Disc Pressing Die5
5
Pass through a 1150 °C zone in 4 minutes
Pass through a 1150 °C zone in 4 minutes
Sinter at 1150 °C by passing the pieces through a 4 cm hot zone at 10 mm per minute: 4 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
2- 59.05 gPlaceholder
- 127.5 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.