Duplex treatment : Improved performance through combined surface treatment processes
We define duplex treatment as the targeted combination of a thermochemical plasma nitriding process with the subsequent deposition of an eifeler PVD coating, carried out in a continuous, non‑interrupted plant process.
This process sequence enables a controlled and reproducible increase in the surface hardness of the tool material. The improved hardness profile provides the optimal basis for the PVD coating and makes a decisive contribution to the coating’s performance, service life, and load‑bearing capacity.
For this technology, we developed a specially tailored nitriding process and successfully integrated it into our alphaP coating system. In this system, plasma nitriding is performed directly upstream of the PVD coating process, ensuring maximum process reliability and the highest quality standards.
In principle, duplex treatment is suitable for all steel materials that can be nitrided and coated.
A proven key application area is tooling for the forming of high‑strength sheet materials. In this field, duplex treatment is regularly and successfully applied in combination with the VARIANTIC® or TiCN coating systems. Of course, combinations with other coating systems are also possible.
Our experienced application specialists will be pleased to support you in selecting the optimal process and coating solution for your specific requirements.
The following advantages result for you:
- Ideal structure of a hardness gradient from the tough-hard tool core, through a higher supporting hardness in the interface, extending to the extremely hard and wear resistant tool surface.
- A considerably increased support effect therefore results for the extremely hard and brittle ceramic wear protection layer.
- The absorbing ability for pressure loads increases significantly!
| PVD coating | Hardness (HV) | Max. operating temperature (°C) | Friction coeff. against steel | Coating thickness (µm) | Color | Applications | Further information |
| Duplex-VARIANTIC® | 3,500 ± 500 | 800 | 0.2 | 2 – 4 | dusky-pink | Forming Punching | Product information |
| Duplex-VARIANTIC®-1000 | 4,000 ± 200 | 800 | 0.6 – 0.7 | 8 – 9 | dark red-gold | Forming | Product information |
| Duplex-VARIANTIC®-1400 plus | 3,000 ± 200 | 800 | 0.2 – 0.6 | 5 – 7 | blue-gray | Forming Punching/fine blanking | Product information |
| Duplex-TIGRAL® | 3,300 ± 500 | 900 | 0.6 | 3 – 5 | dark gray | Die casting | Product information |
Example applications for the duplex treatment:
Blankholder: Segmented tool
Drawing tool: Segmented tool
Treatment Duplex-VARIANTIC®: Mirror finish in assembled status
Material: 1.2379
Base hardness: 58–60 HRC
Workpiece material: CPW 800; 1,7 mm
Lubrication: minimum coil greasing (2 g/m2)
Status quantity: >120.000 parts
Result: The optimized and hard-coated surfaces do not indicate any visible wear traces.
In comparison without coating: A repolishing of the functional surfaces is required every 5000 parts.
Blankholder: Segmented tool
Drawing tool: Segmented tool
Treatment Duplex-VARIANTIC®: Mirror finish in assembled status
Material: 1.3343
Base hardness: 63–64 HRC
Werkstückstoff: CPW 800; 1,8 mm
Lubrication: Coil greasing, slight oiling
Status quantity: >300.000 parts
Result: The optimized and hard-coated surfaces do not indicate any visible wear traces.
Total dimensions: 2.500 mm x 1.100 mm x 630 mm
Drawing rings: Ø 90–100 mm x 70–80 mm
Treatment Duplex-VARIANTIC®: Mirror finish
Material: Vanadis 6/Vanadis 10
Base hardness: 62 HRC
Workpiece material: 1.4301-DDQ-2
Platinum: Ø 144 mm x 2,6 mm
Lubrication: Esso – Umformöl 60
Status quantity: >100.000 parts
Result: No visible wear on the coated active segments.
Workpiece: Querlenkerschale Pkw CPW 800, 4 mm
Tool: 1.2379
Base hardness: 58–60 HRC
Treatment Duplex-VARIANTIC®: Mirror finish in assembled status
Material: 1.2379
Base hardness: 58–60 HRC
Standmenge: 1 Mio. Hub
