Surface treatment in plasma
Quality assurance
In order to be able to offer our customers a consistently high standard, our products are subject to constant quality assurance. All orders of contract treatment are controlled by testing the surface hardness. For this purpose we have modern stationary and mobile testing technology at our disposal. Of course, all measuring and testing equipment complies with the common hardening shop standards.
Contract treatment and plant construction are certified according to ISO 9001:2015.
We carry out the following test work under logging:
- Nitriding hardness depth by means of grinding
- Coating thickness measurement by means of microsectioning
- Microstructure image of the cross section incl. grinding
- Hardness test HV0,05 – HV30: 5 indentations per test series
In the case of specified nominal hardnesses in hardness units according to ROCKWELL C (HRC), the nominal value is converted into hardness units according to VICKERS (HV) in accordance with DIN 50190 150 or DIN EN ISO 18265.
Nitrided layers must not be tested using the ROCKWELL method, but only using the VICKERS method with adapted test loads between 0.5 and 100 kp.
The ROCKWELL diamond pierces the nitrided layer with 150 kp test load and reaches down to the base material. As a result, the hardness values determined are too low.
Following testing methods and equipment can be used
| Surface hardness | VS, Nht and Micrograph | Preparation | Others |
|---|---|---|---|
| Microhardness tester VHT-500 | Microhardness tester Qness | Cutting machine Struers Exotom-150 | Roughness Tester SURFCOM Fa. ZEISS |
| Microhardness tester ZWICK 3212 | Reflected-light microscope NEOPHOT2 | Cutting machine TR-Evolution | |
| Portable hardness tester TIV with measuring head 5 kp (HV5) | Reflected-light microscope NEOPHOT21 | Grinding u. Polishing machine Buehler Beta | |
| Rebound hardness tester | Spot test | Pressure pot for cold mounting, hot mounting press |
All test results are documented. Every order that leaves our production is checked to ensure that it reachs the customer’s requirements. On request, grindings are made, the nitriding hardness depth is checked and a protocol is attached to the delivery. In addition, we test according to customer specifications for special requirements or recommend suitable methods.