The goal of European REACH regulation is to improve health and environmental protection by banning the use of SVHC (Substance of Very High Concern) chemicals while promoting the competitiveness of the European Union's chemical industries. SOURIAU, like most manufacturers, uses hexavalent chromium, one of the substances listed as hazardous, in the surface treatment processes for many of its connectors. Although the European Chemicals Agency has granted provisional extensions of up to 12 years depending on the application, Souriau wished to anticipate this deadline on one of its major product lines.

Souriau's R&D has been working for several years on its composite connectors, which impacts the product and the surface treatment production lines. The first REACH-compliant connectors in the D38999 composite range have been qualified by the European (AECMA cert ) then American (DLA) certification bodies, then approved by Airbus and Boeing before gradually switching in 2019 for the main applications on civil aeronautics programs and many military aircraft programs. Since December 2019, the entire production of D38999 composite connectors is manufactured without the use of hexavalent chromium.

An increasingly important part of Souriau's D38999 range incorporates composite materials either with a nickel-plated finish or with no finish and is mainly intended for civil and military aeronautics applications. The advantage of the PEEK composite used (filled with carbon and glass fibers), is that it offers high mechanical performance in severe environments, is corrosion resistant and weighs less than aluminum.

The challenge for Souriau was to find a REACH-compatible chemical solution for hexavalent chromium-free surface treatment of the connectors. Thomas Pichot, R&D manager at Souriau explains: "We no longer use hexavalent chromium, which was previously needed to improve the adhesion of coatings on the composite substrate of our housings. We have developed the first innovations without hexavalent chromium for motorsport applications and now use for all of our Aerospace and Defense applications a new preparation treatment on composite which allows us to ensure the adhesion of successive metal layers equally well without needing this substance. This builds on the environmental approach we used for aluminum connectors, where we have also qualified hexavalent chromium-free passivation in our zinc-nickel treatment process. All substitute products developed and deployed are now certified non-hazardous and fully compliant with all the various environmental regulations, including REACH. While the challenges are obviously of a technical nature, the benefits are largely ecological, since this changeover has already enabled us to halve the volume of hexavalent chromium used in our Souriau's Champagne production site."

A PEEK plating solution unique in the world

Souriau's particular achievement has been to develop a chemistry that works with PEEK material. Plating on composite pieces has been done for years, but the existing etching process uses Hex Chrome which is banned by REACH regulations. Souriau's solution, unique in the world, is qualified QPL then EN, according to the American standard MIL- DTL-38999 and the European standard EN3645. In addition to its qualification by accredited bodies, the process change has been validated by major aeronautics customers.

As soon as the European REACH regulation emerged, the R&D teams, under the impetus of Souriau's management realized there was a need for a vast program of innovation in surface treatment techniques in order to preserve connector manufacturing in France. The willingness to innovate and "green design" by eliminating hexavalent chromium has strengthened Souriau's achievements and demonstrated its know-how. As Nicolas Paumier, Product Manager D38999 composite explains: "Souriau's proactivity in response to the REACH regulation shows its commitment to its customers, who also face the same issues, whether in terms of innovation, the environment or people's health and safety. This new REACH range will have an impact on our orders for all these reasons, but also because it meets the new European requirements and a global trend of our principals ".