Surface Bonding: Mechanical vs Atomic
A surface bond between two adjacent materials can be achieved 2 ways: mechanical or atomic. And the quality of the adhesive is related to the force required to completely separate the two materials.
Thermal spray provides a mechanical bond. In mechanical bonds the technician is purposefully creating a very rough surface to cause an interlock of the two materials, under high pressure.
Whereas with atomic bonding, the ions of the metals (going from solution to substrate) are connecting to form an ionic bond. Selective plating, with the SIFCO Process® creates a powerful atomic bond which is resistant to cyclical temperature fluctuations and sharp, direct impact. The durability of your surface coating is most important if that coating is subject to a corrosive environment. Assuming that base material is properly prepared, tests run in accordance with ASTM C633‑13 on the SIFCO Process® show that two commonly used nickel deposits had a bond strength exceeding the strength of cement. Furthermore, selective plating provides a precise deposit thickness, while thermal sprayed parts require machining to the required dimension.
If you are having problems with adhesion, determine if your application may be suitable for selective plating. To learn more about how the SIFCO Process is improving the aerospace industry, download our whitepaper.