A whole industry has grown up around PVD tool coatings because of the success of physical vapour deposition (PVD) technology over the past four decades. This industry is a result of the early pioneers in this field.
A gas is delivered into the coating chamber, where it combines with the vaporized metal species to produce the required compound. This is how most PVD hard coating procedures work. Furthermore, all modern coating processes for successful hard coating layers today involves ion-supported hard coating deposition. Ion irradiation during deposition ensures a hard covering that is completely thick and well-adhered.
All substrates undergo a sputter etch prior to deposition to remove any oxide layer, and when high-speed steel equipment is employed, heat is applied to raise the substrate temperature to the region of 425 to 550° C.
Four major types of equipment are now being used to deposit PVD tool coatings, and they all fall under the umbrella term of ion plating.
The way the raw material is vaporized is what differentiates the four varieties
either by evaporation or sputtering
the way that the plasma is created
and the density and energies of ions, electrons, and gas atoms that constitute the plasma.
The four PVD hard coating methods include
balanced and unbalanced magnetron sputtering
cathodic arc deposition
plasma aided chemical vapor deposition, and
electron beam evaporation.
These four PVD methods have many things in common, but they also differ greatly, and these variances can affect the kinds of films that can be deposited in these systems.
Sputter deposition is one of the most expensive and complicated processes. Sputter deposition, on the other hand, allows for more versatility in the types of materials that may be deposited as well as more control over the composition of multielement films.
The requirements for decorative PVD coatings are getting more and more stringent:
- appealing color
- high hardness and wear resistance
- color constancy over time
- corrosion resistance, etc.
Quality standards are getting stricter while production costs are always going down.
Magnetron sputtering undoubtedly has a prominent position among all PVD deposition options, offering significant advantages over rival techniques
This technology allows for the coating of substrates that are less temperature-resistant at relatively low deposition temperatures (usually 170°C), such as plastics, elements of watches especially springs, structurally-hardened materials, porous materials, etc.)
Introduction of reactive nitrogen gas
The process parameters, including the flow of nitrogen utilized as a reactive gas, the chamber's overall pressure, the Ar/N2 ratio, the substrate temperature, and the substrate bias voltage, affect the color of the deposited films.
The nitrogen flow is unquestionably the most crucial of the listed variables since it causes the coatings' color to change from grey (from titanium metal deposition) to yellow when the stoichiometric TiN composition is reached.