Nickel Exposure Series 0

20150716_081701

Nickel Exposure Testing Series 0
Nickel Identification Test Series 0 Testing was performed on nickel coated magnets to determine the efficacy of Sodium Hypochlorite, Sodium Bisulphate, and Ammonia with and without the addition of Sulfur, in identification of exposed Nickel. An additional test using a solution of Ammonia and Dimethylglyoxime was performed which provided the most promising test in terms of quick and safe identification of surface flaws and nickel exposure.

Sodium Hypochlorite
Procedure: Unit was immersed in 8% Sodium Hypochlorite at 22.2 C yielding a Ph of 12.6. At each time point, unit was removed from solution and dried prior to being photographed before both light field and dark field.

LF - Minute 0

LF – Minute 0

DF - Minute 0

DF – Minute 0

LF - Minute 10

LF – Minute 10

DF - Minute 10

DF – Minute 10

LF - Minute 20

LF – Minute 20

DF - Minute 20

DF – Minute 20

LF - Minute 30

LF – Minute 30

DF - Minute 30

DF – Minute 30

LF - Minute 40

LF – Minute 40

DF - Minute 40

DF – Minute 40

Results: Degredation of flawed surface areas leading to exposure of the underlying Neodymium Iron Boron occurred as early as minute 20. No significant change was noted on the unflawed surface areas which would serve to identify nickel. Sodium Hypochlorite is an innapropriate choice for testing of magnet surface coating.
Sodium Hypochlorite and Sulfur Solution
Procedure: Unit was immersed in a saturated solution of 8% Sodium Hypochlorite at a Ph of 12.6 and Elemental Sulfur at 22.2 C. At each time point, unit was removed from solution and dried prior to being observed under both light field and dark field.
Results: Degredation of flawed surfaces did not occur until minute 40 in this solution; however, failure of the magnet occurred rapidly thereafter. No significant change was noted on the unflawed surface areas which would serve to identify nickel. Sodium Hypochlorite and Sulfur solution is an innapropriate choice for testing of magnet surface coatings.
Sodium Bisulphate
Procedure: Unit was immersed in a saturated solution of  Sodium Bisulphate at 22 C yielding a ph of 1.99. At each time point, unit was removed from solution and dried prior to being observed under both light field and dark field.
Results: No changes were noted for more than 7 days at which time degradation of a surface flaw was noted that resulted in complete failure in less than 24 hours. At no time did any observable change occur to the unflawed nickel coating. Sodium Bisulphate is an innapropriate choice for testing of magnet surface coatings.
Nickel Exposure Testing Series 0   8
Sodium Bisulphate and Sulfur Solution
Procedure: Unit was immersed in a saturated solution of  Sodium Bisulphate with a Ph of 1.99 with Elemental Sulfur at 22 C.  At each time point, unit was removed from solution and dried prior to being observed under both light field and dark field.
Results: No changes were noted for more than 10 days at which time testing was discontinued. At no time did any observable change occur to the unflawed nickel coating. Sodium Bisulphate and Sulfur Solution is an innapropriate choice for testing of magnet surface coatings.
Ammonia
Procedure: Unit was immersed in a 10% Solution of Ammonia at 22 C.  At each time point, unit was removed from solution and dried prior to being observed under both light field and dark field.
Results: No changes were noted for more than 10 days at which time testing was discontinued. At no time did any observable change occur to the unflawed nickel coating. Ammonia is an inappropriate choice for testing of magnet surface coatings.

Ammonia and Sulfur Solution
Procedure: Unit was immersed in a saturated solution of 10% Solution of Ammonia with Elemental Sulfur at 22 C. Because the resulting Ammonium Sulfide solution is volatile and yields hydrogen sulfide gas, a second nickel magnet was suspended above the solution to test for reactivity to the gas.  At each time point, units were removed from solution and dried prior to being observed under both light field and dark field.

Nickel Sulfide Patina

Nickel Sulfide Patina

Results: No degradation or failure of magnet was noted for 10 days at which time the testing was discontinued. By hour 1, a patina of Nickel Sulfide was observable across the entirety of the surface of the immersed magnet. No significant changes were noted on the surface of the suspended magnet. Testing of surfaces using this method has some potential. It should be noted that the known toxicity of Hydrogen Sulfide gas and the known carcinogenicity of Nickel Sulfide demands caution when using this methodology.

Ammonia and Dimethyglyoxime Solution
Procedure: Unit was immersed in a saturated solution of 10% Solution of Ammonia with Dimethylglyoxime at 22 C. At each time point, units were removed from solution and dried prior to being observed under both light field and dark field.
Example of Ammonia/Dimethyglyoxime Results

Nickel - 2 minutes

Dimethylglyoxime

Results: No degradation or failure of magnet was noted for 10 days at which time the testing was discontinued. Within 30 seconds of immersion in the solution the nickel was observed to form a pink-to-red patina. Further immersion resulted in a complete change of color of the unit. The speed and simplicity with which this test can be performed along with the greater safety makes this test the most promising of  the solutions tested.

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