Electroless Nickel Plating Testing
Many industries, for example aerospace and oil and gas require specifications to be met, often to extremely tight tolerances. CBE+ Electroless Nickel Plating is tested at CBE+ laboratories using the following methods:
Adhesion testing
The adhesion of a coating to its substrate is essential to the long-term performance of the coating itself. CBE+ laboratories perform bend tests in accordance with ASTM B571. This includes the part being bent over a mandrel in 1800 and the deformed area being examined under a low magnification (4X) for peeling or flaking of the coating from the substrate. Testing can also be carried out in accordance with specification by the following methods, Tape Test, Burnish Test, or thermal shock.
Microsection testing
To carry out a microsection test, a shim of identical material is plated alongside a customer’s component, using the same method. The plated shim is then cut to shape using an abrasive Resin-bonded Aluminium Oxide cut-off wheel to minimise vibration and ensure accuracy.
The resulting sample is then set in a resin, ground, and polished to a smooth finish. The surface of the sample is then etched in Nitric acid to allow the nickel or diffusion layer to be examined under the microscope.
The microscope is internally calibrated on a weekly schedule using a UKAS calibrated stage micrometre.
The specification for micro-section testing is BS EN ISO1463 & ASTM B487.
Microhardness
Hardness is defined as the resistance to indentation and determined by measuring the permanent depth of the indentation. As a rule, the smaller the indentation left in the metal, the harder the metal.
We measure the hardness of metal by using the Vickers hardness test with a square-based, pyramid-shaped diamond used for the indentation. Samples undergo microsection preparation before undergoing the microhardness testing to allow a smooth surface upon which to test.
The hardness tester is calibrated externally annually to UKAS standard, and a calibrated block is used to internally calibrate before each use.
Microhardness methods are suitable for testing metals, ceramics, composites, and almost any other type of material.
The specification for hardness testing is ASTM E384.
Salt Spray Testing
The salt spray test is used to check the corrosion resistance of coated samples, substrates and components which may be prone to suffering from degradation because of salt corrosion.
The test is conducted in a closed salt spray chamber, where the sample is subjected to extended exposure to a specific concentration and volume of saline spray. The length of the exposure time is determined by the material, the coating, and the standard specified.
The salt spray test can be adapted to different levels of corrosion to simulate different environments. As a rule, the more resistant the coating is, the longer the period in testing without showing signs of corrosion. Our expert team are then able to evaluate the part for evidence of corrosion, enabling us to determine the resistance of the sample, ensuring its longevity and reliability.
The specification for salt spray testing is ASTM B117.
Kesternich Testing
Kesternich testing simulates acid rain or industrial chemical exposure to evaluate the corrosive resistance of the coating, substrate, or part itself. The parts or shims are placed inside the sealed chamber and exposed to cycles of moist SO2 and humid conditions. One cycle lasts 24hrs, the testing consists of 10 24hr cycles. After each cycle the parts or shims are evaluated for corrosion.
Our Kesternich testing services are available to customers worldwide.