Hard Chrome Plating on the basis of trivalent chromium compounds
Hard chrome is characterised by a variety of technical properties that are valued in a wide range of industries and, in combination, cannot currently be replaced by any other technology. Because of the dangers posed by chromium(VI), the surface finishing industry has been looking for an alternative for several years. While chromium(III) technology is already used for decorative purposes, this process has not yet been transferred to functional chromium plating. In a joint research cooperation, COVENTYA and Betz-Chrom have now succeeded in developing a stable pilot process for functional coating with chromium(III). The process delivers reproducible hard chrome coatings of high quality.
Our BeGreen Chrome® process deposits a functional hard chrome layer based on trivalent chromium compounds from the electrolyte DURATRI 240. The first customer components have already been successfully coated and are now being tested for their suitability for the corresponding application. We are currently looking for further interested pioneers who want to test a functional chrome plating with chromium(III) on their components. Contact us for a project planning and be part of the chrome plating of a new generation!
Properties of Hard Chrome
Hard chrome is characterised by high hardness, abrasion resistance, corrosion resistance and very good wear resistance. Hard chromium plating extends the technical properties of components and prolongs their service life. Functional chrome plating is used in particular for wear protection in the aerospace, automotive, hydraulics and various branches of mechanical engineering.
Hazardous substance chromium(VI)
National authorities and international regulations such as REACh set strict requirements and limits for the use of hexavalent chromium in surface coatings. Chromium(VI) compounds are mutagenic and carcinogenic. Workers must be protected against exposure and the environment against emissions. The chromium layer deposited by the galvanic process is present as a metal in neutral form – Chromium(0). Hard chromium-plated components are non-toxic and therefore harmless.
The BeGreen Chrome® Process
DURATRI 240 meets the requirements of the surface industry for a more environmentally friendly process by avoiding hexavalent chromium compounds. Our BeGreen Chrome® process is much more complex than conventional hard chrome plating. It requires a multi-part pretreatment series and complex anode technology. Betz-Chrom is willing to meet these challenges and is thus consistently pursuing the self-imposed vision of green electroplating.
800 - 900 HV 0.05
with post-treatment up to 1600 HV
Rmax < 0.1 μm to Rz 70 μm
8 µm: 20 cracks/mm with 200 - 250 nm crack size
35 µm: 10 cracks/mm with 800 - 900 nm crack size
110 µm: 3 cracks/mm with 1.5 µm crack size
Wear resistance (abrasion resistance)
Taber Abraser Test: 1.6 mg / 1000 rotations
Korrosionsbeständigkeit nach DIN EN ISO 9227-NSS
Chrome 50 µm: 120 h Rp 9
Hybrid Nickel 30 µm + Chrom 20 µm: 1008 h Rp 10
Lead and cadmium free (RoHS compliant)
Betz-Chrom has commissioned the independent Institute for Galvanic and Surface Technology Solingen (IGOS) to analyse the coating properties. The tested steel bolts were coated with DURATRI 240 by Betz-Chrom. IGOS carried out a 1008-hour salt spray test in accordance with DIN EN ISO 9227 NSS:2017-07, coating thickness measurement in accordance with DIN EN ISO 2178:2016-11, wear test with the friction wheel method in accordance with DIN EN ISO 7784-2:2016-12 and Vickers hardness test in accordance with DIN EN ISO 4516:2002-10. In addition, the crack pattern of the chromium layer was shown.
BeGreen Chrome® - why green?
Like proud parents, we have given our new process a name: BeGreen Chrome®. “Be” identifies the belonging to the Betz Chrome family. “Chrome” informs about the type of coating. But what does “Green” mean? With this we want to emphasize hard chrome plating on the basis of trivalent chrome compounds. While chromium(VI)-oxide is red-violet, chromium(III)-oxide has a green colour. The avoidance of hexavalent chromium compounds is also a more environmentally friendly process. We hope that our BeGreen Chrome® process will be able to replace hard chrome plating based on hexavalent chrome compounds in the long term. The introduction of BeGreen Chrome® therefore represents an important step in the pursuit of our vision of green electroplating.
Cooperations partner COVENTYA
COVENTYA is a privately held, international company that develops, manufactures and distributes specialty chemicals for the surface finishing industry. COVENTYA has 10 research and development centres worldwide, each with a specific purpose related to the strength of its local industries. Click here to visit the COVENTYA website.
Betz-Chrom – your partner for strong parts
In the sense of a trustful partnership, you will receive highly qualified technical advice from us that is tailored to your needs. We combine over 65 years of experience in surface technology with an innovative and inquisitive corporate culture. Our quality awareness, our occupational health and safety management as well as our measures for environmental protection and energy saving are audited and certified according to DIN standards. As an on-schedule partner with high quality level, we constantly aim to find the optimal process solution for you.
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