INTRODUCTION:-
Elnik Process is a an Autocatalytic Electroless Nickel Process which will readily treat a wide range of metallic substrates, like steel, light alloys, copper, titanium etc & deposits & deposits Nickel without the aid.
The bath is very stable and easy to control. The deposit speed is rapid and constant at approximately 20 Microns per hour under ideal conditions.
Electroless Nickel deposits have uniform thickness over the entire work piece thus maintaining accurate geometr0y and dimensions on the machined parts.
The remarkable properties of the Nickel – Phosphorus alloy (hardness wear & tear resistance and corrosion resistance) can be further improved by suitable heat treatment.
DEPOSIT CHARACTERTICS:
- Phosphorus contents- 6 – 8%
- Hardness- 150 – 550 VH (As plated)
>900 VH (after 1 hour @ 40 °C) - Density- 7.8 – 8.2 (1 micron/dm2 weights approx. 0.080 g.)
- Resistivity- 60 – 100
- Melting Point- 900°C
- Appearance- Bright, uniform/li>
- Non magnetic
- Taber Index – 9 (as plated)
– 2 (after 2 hours @ 650 °C)
High corrosion resistance in most environments.
MAKE-UP:
To a perfectly clean stainless steel or polypropylene tank. Add demineralised water at the rate of 600 ml./lit. Add Elnik A I at the rate 200 ml. /lit and thoroughly mix. Add Elnik B I at the rate of 100 ml. /lit slowly and with good mixing. Make-up to the operating level with DM water, start filtration and heat to 88°C. Check the pH and adjust if necessary to the range 4.6 – 4.9 using ammonia (25%) solution to raise the pH or sulphuric acid (10%) to reduce. The bath is now ready for use
OPERATING CONDITIONS:
| PARAMETER | OPTIMUM | RANGE |
|---|---|---|
| Nickel (g/l.) | 7.0 | 5.5 – 8.5 |
| Sodium hypophosphite (g/l) | 30 | 25 – 35 |
| pH | 4.7 | 4.6 – 4.9 |
| Solution density on make up | 1.050 | 1.043 – 1.057 |
| Temperature | 88 °C | 85 – 95 °C |
| Loading (dm2/l) | 2 | 0.5 – 3 |
| Deposition Speed | 20 microns/hour under optimum/ideal conditions. |
|
| Agitation | Moderate of the work and/of the solution. |
|
| Filtration | Continuous, using 10μ PP Cartridge | |
| Tank turn over | 3 – 8 depending on working conditions. | |
MAINTENANCE:-
The bath must be regularly regenerated by addition of Elnik B I (reducing agent pH control) and Elnik C I (Nickel). The concentration must not be allowed to depart more than 20% from their nominal value.For each gm. of nickel deposited, add
20 ml. of ELNIK B I
15 ml. of ELNIK C I These additions will maintain the pH and concentrations of nickel, reducing agent and stabilizer within the prescribed limits. The pH can be further adjusted by using ammonia solution or Sulphuric acid solution.
Addition of Elnik B I & Elnik C I can be made following a determination of nickel content by simple EDTA volumetric titration.
EQUIPMENT:
Successful electroless nickel operation greatly depends upon use of suitable equipment made of 316 SS, anodically polarized tanks are recommended. certain grades of PP are used.
Heating coils should be ceramic or stainless steel; thermostatic control should maintain the temperature to +/- 1°C to the desired value.
Filtration equipment with PP Pump body and 10 U filter cartridge in PP. The filtration equipment should be able to withstand up to 95°C In case of inadvertent coating of the tank or of bath instability, the reaction needs to be stopped immediately. On method is to cool the bath using a cooling coil of stainless steel through which you should pump cold water. The bath is then transferred to holding tank whilst the main tank is cleaned and stripped of all the Nickel deposited thereafter.
An extraction system to remove fumes/vapours is essential for good health and safety.
CHARACTERSTICS OF THE SUPPLIED CONCENTRATES:-
| PARAMETERS | ELNIK A-I | ELNIK B-I | ELNIK C-I |
|---|---|---|---|
| Density | 1.185 – 1.205 | 1.155 – 1.175 | 1.170 – 1.19 |
| pH | 3.2 – 3.4 | 9.7 – 10.00 | 1.4 – 1.8 |
| Appearance | Green liquid | Colourless liquid | G reen liquid |
| Nickel (g/1) | 35.7 | 66.9 | |
| Hypophosphite (g/1) | 300 | ||
| Ammonia (g/l) | 37 | ||
| Make-up (ml. Ni) | 200 | 100 | |
| Replenishment (m1/g Ni) | 20 | 15 | |
| Shelf life | 1 year | 6 months | 1 year |
STORAGE OF CONCENTRATES:
Concentrates must be stored under cover, in original containers at a temperature between 5ºC– 35 °C Elnik B I is to be stored away from strong oxidizing agents. Keep containers tightly closed when not in use.
HEALTH & SAFETY:
These are acidic and contains nickel sulphate (harmful) Elnik B I contains ammonia and hypophosphite. Contact with skin may cause irritation and allergic reactions. Use of goggles. Hand Gloves are highly recommended. In case of contact with skin, rinse with plenty of water. In case of contact with eye, please wash with plenty of water and seek medical attention. Avoid breathing any vapours and use under good ventilation.
DISCLAIMER:
Our recommendations are made in good faith and are based on our skill and experience. As conditions of use are normally not in our control nor ideal. Ronuk does not give any guarantee or warrantee explicit or implicit and we are not liable to any person or corporate by reason thereof.