PVD Coating

As a further solution to specific wear related applications, TD Coating Centre offers both Titanium Nitride (TIN) and Titanium Aluminium Nitride NANO (NANO) coatings.
Performed through the process of Physical Vapour Deposition (PVD), these coatings are produced in a state of the art Oerlikon Balzers RCS coating system. With their distinctive bright gold (TiN) and dark purple (NANO), these coatings add far more than just an attractive finish. PVD coatings have made their mark on the manufacturing industry through their extensive use throughout the world in the cutting tool market. Although the cutting and machine tool market still remains the biggest application for these coatings, their excellent properties can be taken advantage in many other tooling and component related applications.

In partnership with SOMTA TOOLS, TD Coating Centre focuses its use of these coatings outside of the cutting tool market, assisting its customers to gain further benefit from these coatings superior properties.

As the name suggests PVD is a physical deposition of (in our case) titanium vapour on the surface of a steel. This is a line-of-sight process and is fully computer controlled and performed in a complex coating system made by the world leaders in PVD Coating, (Oerlikon Balzers). The advantages of high precision, high hardness, exceptionally thin coatings performed at medium range temperatures (less than 500 °C) means these coatings can be applied to a broad range of materials and applications and outperforming other processes in their niche.

Properties:
• Micro Hardness of 2300 Hv (TiN) to 3300Hv( NANO)
• Controlled coating thickness of 2-4 microns
• Oxidation resistance up to 900°C
• Process temperature less than 500°C
• Good adhesion to sharp cutting edges
• Low coefficient of friction

Benefits:
• Highest precision and repeatability
• Low distortion
• Good abrasion and adhesive wear resistance
• Excellent for cutting applications
• Can be applied to a wider range of tool steels, such as HSS and Powder Metallurgical (PM) steels
• Preserves highly polished surface finishes

Applications:
• Precision metal working tools and dies (including our range of punches )
• Pierce punches, trim and blanking tools
• Cutting Tools and Inserts
• Taps and Dies
• Plastic Injection Moulding Parts (cores and inserts, screw tips, Slides )
• Blades
• Machine Parts, etc.

As with anything, there is good PVD and poor PVD. We offer superior PVD, by matching the application to the coating required, pre- and post polishing where necessary, as well as assistance with base material selection and heat treatment specifications to make the job work for you.

In many cases, it is not possible to undo certain processes or manufacturing steps that are required to take the advantages that the coating has to offer. This is where our ability and experience with manufacture of precision custom tooling brings out the best performance of our coatings and we can offer a complete manufactured solution. See our manufacturing page for more.

So which PVD coating is best for the Job? TiN (Gold) or TiAlN (Purple) ?
Luckily, the coatings have the majority of their applications in the same range and therefore a critical error can not be made between the two.

Titanium Nitride (Gold)                      Titanium Aluminium Nitride (Purple)
Cost	Most economical	20% more than TiN
Micro Hardness	2300 Hv	3300 Hv
Range of Application	Broadest	Broad
Work materials	Copper based alloys can adhere, otherwise all	All Materials
Coefficient of friction	0.4	0.30-0.35
Max service temperature	600°C	900°C
Bonding strength	Might be better on lower hardness materials*	Might suffer from speckling on certain surfaces
Aesthetic appeal	Best	Good
	*to be confirmed

Most often TiAIN (Futura NANO) is recommended for no other reason than because it is harder and smoother and seems to have a decreased tendency for adhesion to the work materials.

Since there are distinct characteristics that separate the two technologies, there are applications where only one of the coatings would be suitable to add benefit. Here the coatings obviously do not compete.
There are however overlap applications where either of the coatings would add benefit. This would naturally put the two coatings in competition with each other on that application, however choosing the best coating for the particular application usually boils down to two main criteria.
1. Bond strength
Due to the Thermal Diffusion process, the TD coating has a much higher bond strength than that of PVD and is therefore more suitable for very high surface load applications such as pressing of stainless steel and very thick gauge sheet.
2. Precision required
Precision however is the forte of PVD coating and due to its lower temperature application, it is the best when tight tolerances are critical, and need to be maintained once the steels have been heat treated correctly.

If neither of these are primary concerns then experience in the particular application or from a similar application under the same conditions, is necessary to determine the best value to the customer.
Cost always tends to play a role, but since coatings have a leverage effect in cost saving, this potential difference is usually dwarfed by getting the tool to work its absolute best.

For more downloadable info and links regarding this coating and others please visit our Literature & Useful Links