Electroless Nickel Plating Services
The electroless nickel plating services we provide at Alexandria Metal Finishers are used to provide a corrosion and wear resistant surface on a variety of metal substrates. Electroless nickel continues to gain favor in a variety of industries due its combination of desirable material properties and ability to provide complex parts with a very uniform plating thickness. We offer low, medium, and high phosphorous nickel plating to defense, aerospace, and commercial manufacturing standards using manually controlled processes. Electroless nickel offers corrosion and wear resistance as well as a low coefficient of friction, making it ideal for a number of machinery components and other harsh applications. We can carefully control the plating thickness, depending on the grade of material used, resulting in a uniform part that rarely requires additional processing.
Although it has been used extensively for a number of years, electroless nickel is still considered a relatively new plating process, and is misunderstood by many in the industry. This is partially due to the inability of many finishing providers to properly apply the plating. Since electroless nickel plating relies on a chemical reduction reaction, control of the process is critical in obtaining optimum results. A typical EN bath is more sensitive to operating conditions than an electroplating bath, and care must be taken to control the process within relatively tight parameters to achieve the best performance.
Properties of Electroless Nickel
The industry normally identifies electroless nickel coatings according to their phosphorus content:
Low phosphorus <6% P.
Medium phosphorus 6-9% P.
High Phosphorus >9% P.
- High P
- Mid P
- Low P
- %P content
- Hardness (HV)
- Table wear index
- Corrosion resistance
- Electrical resistivity, µΩ•cm
- Modulus of elasticity, GPa
- Slightly magnetic
Phosphorus Content vs. Deposit Properties
Phosphorus content has a great effect on deposit properties and it can be varied over a wide range, typically 3 to 12%. There are distinct differences in the corrosion resistance and hardness properties of low and high phosphorus deposits. In general the higher the phosphorous content the better the corrosion resistance. However, the higher the phosphorous content the lower the magnetism. Below are some general guidelines of the effects of phosphorus content in the deposit on physical properties:
- Hardness - deposit gets harder as phosphorus content decreases
- Wear - deposit is generally more wear-resistant as phosphorus decreases
- Electrical - conductivity increases as phosphorus content decreases
- Solderability - deposit becomes more solderable as phosphorus decreases
- Melting Range - melting range increases as phosphorus content decreases
- Corrosion Resistance - deposit is generally less corrosion-resistant as phosphorus decreases
- Corrosion Protection - typically, corrosion protection decreases slightly as phosphorus content decreases
- Elongation - ductility is highest at less than 2% P and greater than 10% P