HOW TO MEASURE THE MULTI-LAYER PLATING THICKNESS

September 27, 2020

How to measure the multi-layer plating by HUATEC TG-100E

 

Example: The measurement of the thickness of the multi-layer deposits consisting of coppernickel and chromium plating on the steel substrate . The thickness of the component layers is 0.4μm of chromium, 14μm of nickel, 10μm of copper.

  1. Use the rubber wipe away the passivation films on the surface of plating on the article to be measured
  2. Depress the testing head vertically on the surface of the article to be measured, applied an adequate pressure until without any leakage.
  3. Electrolytic solution A2 is selected from table2, the cell must be filled with 2 ml of the electrolytic solution by using a dropper. The cell will not be filled full. (The solution level is about 3 mm from the opening of the cell)
  4. Insert the pipette into the bottom of the electrolysis cell. Repeat suck several times, in order to remove the air bubble from the cell, enables the electrolytic solution to contact completely with the chromium plating.

Note: When measuring the chromium plating placing the stirrer is not a requirement.

  1. Depress the T & Cr measurement button.
  2. Insert the signal plug into the hole of the screw of the electrode, attach the red signal clip to the plated object and be sure that a proper connection has been done.
  3. Press the measurement button, the stirrer begin rotating, while the buzzer alarms, the measurement will be stopped automatically, the thickness of 0.4μm has been displayed on the indicator, repeat press the measurement button 1~2 times, and buzzing before pressing the stop button. Record the thickness of the chromium plating (the measurement values is based on the values obtained from first buzzing).
  4. Clean up the used electrolytic solution by using the pipette without rising the mount of the cell. Rinsing the cell 1~2 times with deionization water before filling the cell with 2ml of the electrolytic solution A5 (refer to Table 2, the electrolytic solution A5 for nickel plating on copper substrate), and then placing the stirrer to giver position.
  5. Repeat the step 7 as above and record the thickness 14μm of the nickel plating.

 

  1. Repeat the steps 7, 8 as above and record the thickness of 10μm of the copper plating.
  2. Clean up the used electrolytic solution by using the pipette. Rise the testing head. Remove the article.
  3. Clean up the internal surface of the cell and gasket by rinse water and wiping. Be sure that there is not any oxidation products on them before they are replaced back.

The formulations and preparation methods of the electrolytic solutions

 

Requirement: The electrolytic solution requires preparation from the analytical pure grade of the chemicals and the distilled water.

 

Symbol Name Molecular formula Preparation methods
A2 Phosphoric acid H3PO4 Use water to dilute 127ml H3PO4 to1000ml.
A3 Hydrochloric acid HCl Use water to dilute 175ml HCl to 1000ml.
A4

Ammonium

nitrate

NH4NO3

Use water to dissolve and dilute 800g

NH4NO3, 10ml NH3·H2O to 1000ml.

Ammonia

aqueous

NH3·H2O
A5

Ammonium

nitrate

NH4NO3

Use water to dissolve and dilute 400g

NH4NO3 40g NaSCN to 1000ml.

Sodium

thiocyanate

NaSCN
A6 Sodium nitrate NaNO3 Use water to dissolve and dilute 5ml HNO3, 100g NaNO3 to 1000ml.
Nitric acid HNO3
A7

Potassium

thiocyanate

KSCN Use water to dissolve and dilute 180g KSCN to 1000ml.
A8 Sodium chloride NaCl Use water to dissolve and dilute 100g NaCl to 1000ml.
A1、A10   At present, those formulations not been published, for purchase. Please contact with us
 
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