Processes and services

The Abrasive Blasting is an impact surface treatment technique used to obtain an excellent grade of cleaning and polishing of the surfaces.

The sand blasting process is an abrasive method for mechanical cleaning used on metallic and non-metallic parts, and consists in impacting aluminium oxide beads (corundum) or silica (glass beads), at high velocity, on parts surface.

For aeronautics, sand blasting is a special process, for that Elhco established procedures according to AIPS 02-02-002 specification.

In order to provide a high-precision finishing to our customers we use different techniques selective masking and lacquers.

Besides the classical lacquers, we use different tapes and special taps, which are custom made and so adapting to any geometry.

The trichloroethylene is a substance used usually as degreasing agent for metallic parts.

Elhco has a small dimension machine equipped with a closed recirculation system, which is totally safe for the personnel and the environment.

As part of our commitment to protecting the environment, we have reduced the use of this substance (trichlorethylene) due to its high toxicity, so we only use it in processes where it cannot be replaced.

The cleaning by Ultrasounds is equally efficient as by trichloroethylene, and is totally safety.

The cleaning by ultrasounds is based in the generation of high frequency sound waves, normally from 20 to 80 kHz, in a liquid. The effect produced is called cavitation and is formed due to generation of high and low pressure zones in the solution.

The ultrasounds assure a high precision cleaning for parts with different geometries, both with small channels or tight holes, where any other method of cleaning are way less efficient.

Our installation fo ultrasounds have a capacity of 1100 litres, with ultrasounds power of 10 W/L and a frequency of 20-40kHz.

The cleaning and degreasing by aqueous alkali media can be applied to any type of part and is generally used for preparation of the materials before plating.

We have different tanks with different cleaning media, with a maximum volume of tanks of 1000 L.

In the cathodic electrolytic cleaning media the parts are connected to the cathodic part of a current rectifier and are negatively charged.

Our experience with this process drive us to develop a robust process, safety and efficient for different types of parts and materials. We have different working tanks with a maximum capacity of 1200 L.

In the anodic electrolytic cleaning media the parts are connected to the anodic part of a current rectifier and are positively charged. A flux of continuous current pass through an alkali electrolyte, which serves as conducting medium and the electrolysis of water takes place.

Acid pickling is applied in order to eliminate any layer of oxidation that may be on the surface of the parts. We use different solution, both commercial and homemade, which are customized depending on the material type.

We have different working tanks with a maximum capacity of 1000 L.

Acid activation is the last step in the preparation phase of the materials, before plating. It is done with hydrochloric acid in working tanks with a maximum capacity of 1000 L.

Zinc Amalgam is a process for the preparation of aluminium surfaces before coating with Elctroless Nicke-Phosphorus or Electroless Nickel-Phosphorus-Teflon. Zinc Amalgam is a commercial product and the process is done in working tanks with maximum capacity of 1000 L.

Wood’s Nickel is a type of electrolytic activation for stainless steel, which is done in an electrolytic plating bath based on nickel chloride and that has a very low pH. Stainless steel has a very rapid natural passivation that is difficult to eliminate. Wood’s Nickel contains a large quantity of hydrochloric acid and is designed to dissolve the passivation layer of the stainless steel while in the same time plates on the surface a very fine layer of nickel. We have different working tanks with maximum capacity of 1200 L.

Strike Nickel, as Wood’s Nickel, is used for plating a very fine layer of nickel for increasing the adhesion of the other plating baths. The solution used in the process is commercial and the process is carried in working tanks with capacity up to 1500 L.

Electroless Nickel-Phosphorus Plating is the most important catalytic plating process used in the last two decades. The elctroless nickel-phosphorus layer is a double alloy of nickel and phosphorus with different ratio nickel:phosphorus. At ELHCO we have three types of electroless nickel-phosphorus platings: low content of phosphorus (2-5% by weight), medium contant of phosphorus (6-9% by weight) and high content of phosphorus (more than 10.5 % by weight). The plating processes are automatized and we have working tanks with capacities up to 2000 L.

Electroless Nickel-Phosphorus-Teflon is a plating process derived from Electroless Nickel-Phosphorus, where together with the nickel-phosphorus layer a Teflon layer is co-deposited. The nickel-phosphorus layer can be of medium or haigh phosphorus content, and the layer of Teflon has 20-30% by volume content in Teflon.

We do Electrolytic Nickel based on sulfamate nickel salt and is generally used as base coating for others coatings as gold or silver. Also, it can be used as final finish, when a pure nickel coating is obtained, though the mechanical properties of these coatings are less interesting that the ones obtained for nickel-phosphorus coatings. For this process we have working tanks with capacity of 235 L.

The main applications of zinc-ncikel coatings are for automotive and aeronautic industries. It is used for prts that go to hydraulic connections, screws, fasteners, brake discs, etc. For the aeronautic industry we perform the process according to AIPS 02-04-006 specification.

Gold plating is used mainly for electronics, normally for integrated circuit boards, where it offers a great resistance to corrosion and an elevated current conductivity to the copper layers. We have both rack and barrel processes, with working tanks up to 80 L.

Tin Plating is used for electronics, where substitutes lead. The coatings are soft, ductile and oxidation resistant, have a good conductivity, corrosion resistance and improve the solderability properties for substrates that are difficult to weld. We have both rack and barrel processes, with working tanks up to 150 L.

Silver coatings offer the highest electric conductivity of all the metals, but the main drawback is its rapid oxidation. For engineering reasons, silver coatings are recommended for parts that aer to be welded, where a high electrical and thermal conductivity are required, as well as wear resistance and a good corrosion protection. We have both rack and barrel processes, with working tanks up to 140 L.

Copper coatings are used mainly as base coating before other coatings, usually nickel, but also is used as unique coating, both for transforming non-conducting materials to conducting ones, as well as to improve the electrical conductivity for integrated circuit boards. We have both rack and barrel processes, with working tanks up to 520 L.

The passivation of corrosion resistant steels is used for strength the natural layer of passivation of the steel (superficial oxide layer) with the aim of improving its resistance to corrosion. Depending on the type of passivation, the process gives to substrates a better behaviour towards different factors of environmental corrosion. Also, it cleans the surface of free iron particles and offers to steel a better resistance to fatigue.

Passivation with chrome (III) process is used as supplementary protection and corrosion resistance improvement of the zinc-nickel coatings. Due to chrome (III) derivatives, the finish has an iridescent grey-blue colour. We have working tanks up to 1200 L.

The layers obtained with sulphuric acid are usually transparent, thicker and more porous than the ones obtained with chromic acid, and for that are better substrates for painting.

Hard anodizing is used to obtain a finish with the hardness equivalent of a casting steel and with the lightness and the resistance of aluminium. In the hard anodizing process the obtained layers are thicker than in the case of normal sulphuric acid anodizing or chromic acid anodizing.

The layers obtained with chromic acid anodizing are opaque, softer, and thinner and have better ware resistance than the anodized layers obtained with sulphuric acid. Also, the chromic anodized layers are more ductile and for similar thickness, have more corrosion resistance than the sulphuric anodized layers.

Aluminium satinate is an chemical attack of aluminium with an alkali solution, and a sparkling white or clear grey finish is obtained. Usually is used for decorative reasons.

The Alodine process is a chemical conversion process of aluminium during which a layer of oxide/hydroxide of aluminium layer is obtained. This layer have at least 1 micron, and is obtained by chemical action of an acidic solution of chromates. The Alodine layers offer a certain grade of corrosion protection and are a good base for organic finishes.

The heat tretments can be done in controlled atmosphere (at vacuum) in ovens that work up to 450°C.

The heat tretments can be done in controlled atmosphere (at vacuum) in ovens that work up to 450°C.

We have different working tanks and process in order to eliminate all the type of layers for all the plating and surface finishing that we perform.

We have different working tanks and process in order to eliminate all the type of layers for all the plating and surface finishing that we perform.

We have different working tanks and process in order to eliminate all the type of layers for all the plating and surface finishing that we perform.

We have different working tanks and process in order to eliminate all the type of layers for all the plating and surface finishing that we perform.

We have different working tanks and process in order to eliminate all the type of layers for all the plating and surface finishing that we perform.

We have different working tanks and process in order to eliminate all the type of layers for all the plating and surface finishing that we perform.