|
ALUMINAL coated fasteners show their advantages when being used in the maritime sector
+ + + Surface protection with pure aluminium for rack and barrel plated goods in serial production
Aluminal works with a new galvanic coating process doing without aqueous solvents. The surface of Aluminal is a coating made of pure aluminium on metallic parts. It gives additional safety for higher demands when other coatings have gained their limits. Being used in the maritime sector they show their high benefits for the use in extreme conditions. Some of the advantages for the maritime industry are: resistance against sea water, maximum corrosion protection as well as cost reduction for maintenance by longer intervals and the possibility of recoating the used parts.
The change being caused by the innovation of the industrial galvanic deposition of aluminium can be compared to the replacement of usual coating procedures by the deposition of zinc - nickel. Established galvanic processes do coatings based on aqueous solvents. Aluminal coatings on metal parts however work under exclusion of water and air. The parts to be coated run on racks or in barrels from the aqueous pre-treatment to an inert gas cell filled with nitrogen. By the means of a special electrolytic recipe and organic solvents, the so called aluminization takes place in this cell. Here we add electricity for dissolving the aluminium out of an anode into the solvent and onto the parts to be coated. Further treatments happen under normal atmospheric conditions.
Maximum corrosion protection / resistance against sea water atmosphere:
Maintenance departments and operators of maritime facilities ask for a rate of attendance as low as possible for hard chemical and climatic conditions. Aluminal coated parts meet the requirements of high corrosion protection with a layer of galvanically deposited aluminium and a minimum layer thickness of 6µm. In the salt spray test according DIN EN ISO 9227:2006 the advantages of Aluminal are obvious: The surface is approximately 30-50% more resistant than established systems to the formation of red rust. Due to the cathodic protection of coatings in cloridic aqueous solvents the part is also protected against corrosion, also in sea water. Consequently maintenance clearance is reduced leading to lower costs for attendance.
Especially for maintenance reasons it is possible to add a PTFE coating. This increases the protection against mechanical wear when being fit and improves the gliding properties for the use of fasteners. That is why with Aluminal there are no voluminous corrosion products as with layers based on zinc. Hence the coating cannot be blast by the corrosion products and does not damage the parts additionally. Should however a part fail there is no need to destroy it when removing as normally necessary for coatings based on zinc. It can easily be removed and recoated due to the little corrosion products. This means lower waste and consequently lower costs for the operator.
No hydrogen embrittlement and no mechanical impact on the base material:
Even high strength parts can be protected. The Aluminal technology excludes the danger of hydrogen embrittlement and reduction of the strength of the base material. High strength parts tend to hydrogen embrittlement and brittle break afterwards to established procedures. The strength can also be reduced unwantedly by high coating temperatures or after treatments (elevated temperature age hardening, baking). Aluminal eliminates these disadvantages as it is a low temperature process and no hydrogen arises. Generally a strength of 1.000 Mpa is the limit for galvanically coated parts. Aluminal has already coated spring steel of 2.000 MPA without the need of heat treatment afterwards.
The Aluminal coatings are applied to the parts in Montabaur – Heiligenroth. When starting serial production in 2006 industrial coating of rack and barrel plated goods has been realised. On an area of about 45.000m² a production hall with two equal lines has been erected.
For more information: www.aluminal.de
Posted Januar 22, 2009
|
+
+ Media Links + +
For more information, media details or
sample copies please contact
wilhelms@pennwell.com
www.sicking.de
|