» Applications and uses of the ELNIP 13® process
The application of the ELNIP 13® coating can be recommended whenever one or more of the following properties is required: resistance to corrosion; improvement of friction; resistance to wear; increase in surface hardness; brazing with tin lead alloys; further coatings with precious metals; ease of degassing.
All these qualities provide the user with many considerable economic advantages: an increase in the lifetime of the part; a reduction in weight thanks to the replacement of a light nickel-plated alloy; a lower cost due to the use of a common nickel-plated material rather than a special material.
» Main industrial sectors where the ELNIP 13® TREATMENT IS OF INTEREST
» Food industry
» Pharmaceutical industry
» Car industry
» Motorcycle industry
» Textile industry
» Hydraulics and pneumatics
» Precision mechanics
» Technical data
|2||MELTING POINT||Abou 890°|
|3||SPECIFIC WEIGHT||7,92 g/cm3|
|4||COEFFICIENT OF EXPANSION||
13X10-6 CM/CM °C at normal temperature.
steel 12x10-6-6 cm/cm °C
copper 17x10-6 cm/cm °C
brass 19x10-6 cm/cm °C
duralumin 23x10-6 cm/cm °C
60 micro-Ohm cm2/cm at normal temperature.
This resistivity depends on the quantity of phosphorus in the coating and the heat treatment performed.
|6||MAGNETIC SENSITIVITY||4% (Electrolytic nickel=37,3%)|
|7||MODULUS OF ELASTICITY||Young’s modulus or the modulus of longitudinal elasticity "E" is 20.000 ± 1.000 Kg/mm2|
|8||HARDNESS||Thanks to its content of phosphorus, this deposit has a considerable hardness equal to about 500 Vickers. Following a heat treatment at 290° and over, a further increase in hardness is achieved, reaching up to 950÷1050 Vickers.|
|9||DUCTILITY||At room temperature. Owing to its considerable hardness, this coating is not very ductile. In its unrefined state, it can withstand an elongation of 2,3 % before the first cracks appear. This limit can be increased by means of a heat treatment.|
|10||ABRASION RESISTANCE||The resistance to wear is equal to that of hard chromium when it has a hardness of about 1000 HV.|
|11||COEFFICIENT OF FRICTION||The coefficient of friction is considerably low, as the phosphorus contained in the alloy is an excellent self-lubricant.|
|12||RESISTANCE TO SUDDEN CHANGES IN TEMPERATURE||This coating shows no cracks when, having heated it to 200 °C, it is hardened in liquid nitrogen at -195 °C or in mercury at room temperature.|
|13||ADHERENCE||On steels and copper alloys, the adherence of this deposit varies from 35 to 45 Kg/mm2. To achieve a better adherence on aluminium or steel alloys, a one hour annealing treatment is required at 150 ± 180 °C.|
|14||REGULARITY OF THE COATING||However irregular the shape of the part, this coating reproduces the exact form of the supporting surface. With the normal industrial procedures, it is possible to guarantee ± 1% micron.|
|15||WELDABILITY||This coating can be welded perfectly to silver or tin-lead alloys. A thin layer of deposit, from 5 to 10 microns, is sufficient for welding aluminium or stainless steel.|
|16||REFLECTIVE CAPACITY||The hardness of this coating enables it to undergo an optical polishing up to 1/4 of a wavelength. Under extreme ultraviolet light, i.e. between 400 and 1000 angstrom, its reflective capacity is 50%.|
» Table of porosity after 120 hours of exposure to saline mist
Compared to traditional chromium-plating treatments, ELNIP 13®
When in contact with foodstuffs, the coating has shown negative results with regard to the yielding of nickel, thus complying with the American and European regulations.
In fact, particular conditions of use and maintenance of production plants (presence of corrosive and oxidizing substances, washing with sterilizing products), have had a considerable influence on redirecting the choice of protection away from the type previously used (with cadmium, zinc and paint) towards the ELNIP 13® treatment.
Moreover, this solution has, in some cases, enabled "nobili" materials such as stainless steel and bronze, to be replaced with other materials that are not as special but which have technical characteristics that are more suitable for their specific use.
As previously seen in point 8, concerning the hardness, higher temperatures need to be reached only if a harder surface is required. Some metals may not withstand such temperatures; to avoid any possible problems, the technicians are available to give advice.
Protection and masking
There are no limits with regard to the protection and/or masking of the coating: in fact, bores, pins, internal and external diameters can all be protected. However, the only limit is represented by the high cost of these operations which are all done exclusively by hand; therefore, we would suggest checking the real need to perform these operations together with the technicians.
Hardness of the base metal
The base metal need not be hard in order to achieve maximum resistance to wear.
The base metal must only be able to withstand the working load without excessive bending.
However, great care must be taken when choosing the hardness of the metal when resistance to wear is required due to strong impact loads which could wear through the coating when the metal base yields.
For this reason, it is often necessary to subject the materials to treatments such as stabilizing, hardening, annealing, tempering, casehardening, etc. In these cases, it should be borne in mind that although stabilization, annealing and tempering do not cause any problems, to guarantee a good adherence to the surface, hardening and casehardening require a preliminary micro-sandblasting.
Carbonitriding is difficult while nitriding should be excluded.
Applicability to metals
The ELNIP 13® coating can be applied to the following metals:
COPPER BRASS BRONZE
ALUMINIUM AND ITS ALLOYS
Application of the ELNIP 13® process must be assessed each time when dealing with special assembled parts that include components made of different materials.