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| High Temperature Applications |
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Higher Hci materials can be used as high as 200°C, moderate Hci materials should be used around 150°C. Low Hci materials should be used under 100°C |
SmCo can be used at substantially higher temperatures than NdFeB. The material can take continuous temperatures above 250°C |
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| Loss of flux density at elevated temperatures (see temperature effects on magnets for more information) |
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Loses 0.11% of Br/°C. See Temperature effects on Br and Hci of NdFeB |
Loses about 0.03% of Br/°C |
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| Humid environments |
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Surface treatment should be used. Options are nickel, IVD or polymer coatings such as PR1010, PR1020, or PM1000. Oxidation can be a problem |
Surface treatment is not required. Does not oxidize |
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| Hydrogen rich atmosphere |
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Not recommended, hydrogenation occurs, causing the magnet material to disintegrate |
No known adverse effects |
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| Cost of part |
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Lower cost generally |
Typically higher cost than NdFeB |
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| Radiation environment |
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Can be damaged by radiation, mainly gamma rays |
S2471 and higher grades are very stable in radiation environments |
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| Mechanical Strength |
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Mechanically very strong, not as brittle as SmCo |
Brittle |
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| Clean Room environments |
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Surface treatment is recommended |
Surface treatment is not required |
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Vacuum Applications |
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Does not need to be coated, however, if desired, Nickel or IVD is recommended. Polymer coatings such as PR1010 can be used, but not recommended in ultra high vacuum or high temperature applications in vacuum due to outgassing. Nickel and IVD are metallic and therefore do not outgas |
Surface treatment is not required. However, the material is fairly porous; parts may outgas for a limited duration before high vacuums can be achieved |
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| High field requirements |
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Can achieve much higher fields, higher energy products achievable (55 MGOe available). |
Highest energy product materials are S3264 and S3069, generally very difficult to obtain higher than 30 MGOe. |
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| Cryogenic temperatures |
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Only special formulation grades can be used (call for more information on this) |
Works well in cryogenic temperatures. |
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| Aerospace applications |
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Gaining popularity in aerospace applications. Being used with and without surface treatments. Used on aircrafts, missiles, and satellite programs very successfully. Also qualified and used on the Space Station |
Very popular in aerospace and defense applications. Has substantial history in military, aerospace and defense applications |
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| Salt Environments, open seas, and salt spray environments |
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Care should be taken, surface treatment MUST be used, limited life should be expected |
Stable in this environment |
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| Acid environments |
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Surface treatment is necessary, limited life can be expected |
Stable in this environment, however, qualification tests recommended |
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| Alkaline environments |
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NeSurface treatment is necessary, limited life can be expected |
Stable in this environment, however, qualification tests recommended |
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| Thin walled, thin cross-section applications (a dimension below 0.040") |
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Mechanically stable, parts have been made as thin as 0.008” thick |
Not very good in very thin cross-sections. Under 0.020” is not recommended |
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| Single piece large parts |
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Better than SmCo, larger blocks can be sintered |
Larger blocks (over 3” in any dimension) is challenging |
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| Nickel Plating per military specifications |
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Not available – Plating is done to proprietary specifications, only Electrolytic Nickel is available |
Electroless and electrolytic nickel plating is available. Mil-C-26074 can be complied to |
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| Plating per military specifications |
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Not available. All platings are done per proprietary specifications. |
Not typically used. Call factory for more information |
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| PR1010 coating |
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Available |
Available |
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| Radial ring configuration (so as to obtain a true radially oriented field) |
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Available for custom parts. |
Not available |
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| Sensitivity of Flux Density, Br, and Coercivity, Hc, to temperature changes |
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The Temperature Coefficient of Br (%/°C) ranges from NEGATIVE (0.11 to 0.13). Higher coercivity materials (>20 kOe) are closer to negative (0.11)
The Temperature Coefficient of Hc (%/°C) ranges from NEGATIVE (0.51 to 0.77). The higher the intrinsic coercivity, the lower the Temperature Coefficient of Hc |
The Temperature Coefficient of Br (%/°C) ranges from NEGATIVE (0.03 to 0.04). Series Sm2Co17 are less sensitive to temperature changes (around negative 0.03) than SmCo5 (around negative 0.04)
The Temperature Coefficient of Hc (%/°C) ranges from NEGATIVE (0.15 to 0.24). Series Sm2Co17 are less sensitive to temperature changes (around negative 0.15) than SmCo5 (around negative 0.24) |
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