Hardness of Electroless Nickel Deposits
Hardness is an important property of electroless nickel and is often one of the main reasons why it is applied. The hardness for the family of electroless nickel coatings are listed below:
It is important to note that deposit hardness does not always correlate directly to wear resistance in a particular application. The coating lubricity, smoothness as well as the wear mechanism and mating surface all play a critical role in performance.
The graph below illustrates the effect of heat treatment on hardness of a high phosphorus electroless nickel deposit. Please keep in mind that low phosphorus coatings (1-3%P) will reach a maximum hardness when heat treated at 750 F for 20 minutes. Continued heat treatment will reduce hardness to just under 800 HK.
|
EN Deposit Type |
Hardness HK100 | Hardness HK100 (Heat Treated) | |
| ACN -2 1-3% P | 700 | 1000 | |
| ACN - 6, 8, 9 6-9% P | 550 | 920 | |
| ACN - 10, 11, 12 10-12%P | 510 | 510 |
It is important to note that deposit hardness does not always correlate directly to wear resistance in a particular application. The coating lubricity, smoothness as well as the wear mechanism and mating surface all play a critical role in performance.
The graph below illustrates the effect of heat treatment on hardness of a high phosphorus electroless nickel deposit. Please keep in mind that low phosphorus coatings (1-3%P) will reach a maximum hardness when heat treated at 750 F for 20 minutes. Continued heat treatment will reduce hardness to just under 800 HK.