Technology

SAM Coating GmbH has equipped itself with system technology from the market leaders IHI Hauzer Techno Coating B.V. (based in Venlo, Netherlands), Ecoclean GmbH (based in Frankfurt, Germany) and Amsonic-Hamo AG/SA (based in Biel, Switzerland). Various coating techniques are combined in the coating system so that customers can be offered a very wide range of high-quality PVD/PACVD coating systems. Below you will find an overview of the coating technologies used.

Arc Vaporization

Arc evaporation is a form of PVD (physical vapor deposition) technology. Historically, arc evaporation technology originated from electric welding technology and was then used for hard material coating.

In this process, the vaporization material, which must always be electrically conductive, is placed in a vacuum chamber as a solid plate in any arrangement (horizontal, vertical, upside down) and connected as a cathode (negative potential). As with electric welding, contact is briefly made with the anode, creating an electric arc. The base of the arc is concentrated on a small focal spot a few µm in diameter and moves on the surface of the vaporization material (usually magnetically confined). Due to the high energy density, the material vaporizes directly without forming a large-area melt.

This creates a highly concentrated plasma in the form of a steam club. The product to be coated is then passed through this steam lobe - usually rotating several times to create a coating on all sides.

This technique can therefore be used to deposit metallic coatings or - with the addition of reactive gases such as nitrogen (N2), oxygen (O2) or acetylene (C2H2) - nitride, oxide or carbon-containing coatings such as TiN, AlTiN, TiSiN, TiCN, CrCN.

The nitride coatings are characterized by a very high hardness (~HV 2500-3500 / diamond 10,000 HV), which is why they are suitable as wear protection coatings for tools or components (in automotive engineering).

Arc technology is characterized by the following features:

  • High coating rates (1-3 µm/hr)
  • High ionization (high plasma density) resulting in very dense layers with excellent adhesion
  • As the base material is cooled, little radiant heat is generated, i.e. temperature-sensitive materials such as plastic can be coated at temperatures below 100°C
  • A wide range of mixed vaporization materials (e.g. Al-Ti) can be vaporized without changing the mixing ratio, as no liquid melt is formed
  • The evaporation source can be arranged in any orientation (horizontal, vertical, upside down), which allows great freedom in the machine concept.

Sputtering process (atomization technology)

Atomization technology is a method of PVD coating technology. In this method, the coating material is atomized by ion bombardment from an inert gas - usually argon - i.e. converted into a vapour phase.

Applying an electrical voltage of several 100V between the coating material (cathode) and an anode (usually the chamber wall of the vacuum system) ignites a gas discharge containing electrons and positive argon ions. The ions are accelerated so strongly by the cathode that when they hit the coating material, they knock individual atoms out of the surface through mechanical momentum transfer and are thus transferred to the vapor phase. This allows objects exposed to this vapor to be coated.

In order to increase the ion density of the coating material and thus the coating rate, strong magnets are installed in the cathode, which magnetically trap the ions. This is referred to as "magnetron sputtering". As the coating material itself remains in a solid state during the process, a variety of mixtures of different metals (e.g. AlTi, AlTiV....) can also be deposited without the mixing ratio changing over time.

In addition to the inert argon gas, a small amount of reactive gases such as oxygen, nitrogen, acetylene or other gases can be added to deposit oxidic, nitridic or carbonaceous coatings (e.g. SiO2, TiN, TiCN....). As a result, a much greater variety of coatings is possible with this technique than with any other (e.g. arc evaporation). These coatings show relatively few defects, are very smooth and are therefore particularly suitable for decorative coatings (e.g. TiN, CrN, ZrN, TiCN......).

Due to the smoothness of the coatings, they are also used in tribological applications, e.g. in the automotive market, e.g. CrN, Cr2Nand various combinations of diamond-like coatings (DLC).

PACVD

PACVD or PECVD is the abbreviation for 'Plasma Assisted (Enhanced) Chemical Vapor Deposition', or plasma-enhanced chemical vapor deposition.

While in PVD technology the coating material is usually liquefied in solid form and, if necessary, by adding heat, in CVD technology it is supplied in the gas phase. To produce diamond-like carbon coatings (DLC), for example, a hydrocarbon such as acetylene C2H2 can be supplied, which is cracked in the plasma and thus made available for coating.

Such coatings are mainly used in tribological applications as low-friction and wear-resistant coatings in automotive engineering.