SAMBIX specializes in plating metal parts used in general industry. We do plating treatments in zinc, nickel, tin as well as chemical conversion treatments.

surface treatment technnologysurface treatment technnology

Concerning whisker acceleration testing with an ultra-long time length

In order to confirm the non-formation of whiskers and guarantee the quality of our company’s patented non-whisker method for zinc plating, Zero Chromium S, we carry out testing once a month at 100℃ for 72 hours.
We were requested by our customers to perform a test with a longer period to see if it was certain that whiskers would not form. A 2000 hour acceleration test was carried out.

1.Test specimen

On February 4, 2004 the 10cm by____ 5cm specimen was treated on the mass production line (M radio control range 3.2-3.6, that day 3.4) with non-whisker zinc plating, hexavalent chromate anti-rust treatment.

2. Acceleration testing and observation

On February 2, 2004, the test specimen was placed in a heat circulation thermostat oven at 100℃ plus or minus 3℃ for the acceleration testing. Every 500 hours, it was taken out and observed under a 20-60 power substance microscope. After 2000 hours, the specimen was observed under a scanning electronic microscope.


As summarized in chart 1, the existence of whiskers was checked every 500 hours. The photos show the external appearance after 2000 hours as well as a scanning electronic microscope photo after 2000 hours.

Chart 1 Results of observations

Acceleration time (H) existence of whisker development
500 no whisker development
1000 no whisker development
1500 no whisker development
2000 no whisker development

Photo 1 external appearance after 2000 hours

Photo 1 external appearance after 2000 hours

Slight traces of Hillock like formations were confirmed at 1500 magnification, but whiskers did not develop.

Photo 2 under a scanning electronic microscope after 2000 hours

Photo 2

Even when an ultra-long testing period was carried out for whisker acceleration, whiskers did not develop due to the plating film restraining the internal stress (patented).