COPPER DAY - NOVEMBER 16, 2017 - ENSIL-ENSCI LIMOGES
38 PARTICIPANTS - 8 CONFERENCES
The program of the second copper day organized by the A3TS Limousin branch brought together key players in the profession, with presentations on the geo-political use of copper, its metallurgy and the associated surface treatments.
The participants of the 1st day of 2015 have again answered the call, with a strong common interest to have a day dedicated to this material, which enters both in everyday objects, but also on advanced applications, where there is no substitute (marine environment, space, ATEX environment).
Mr. CHRISTMANN, an expert at the European Commission, reminded us that Chilean deposits are 20% of the most productive, but that the smelters and applicators are much more widely distributed throughout the world. The economic and especially the societal impact was discussed so that everyone has a more concrete vision of our resources and their wise use.
This resource approach was then continued by Olivier TISSOT from ECI who recalled the different families of alloys, their heat treatments and the properties required for each application.
The CuBe alloys from NGK BERYLCO are suitable for a wide range of applications in terms of mechanical strength, not only in everyday objects but also in safety systems where maximum performance is required.
Thierry TURPIN of STAINLESS continued on the mechanical applications by bringing arguments on the use of ToughMet, CuNi15Sn8 alloy whose mechanical characteristics come in complement of CuBe. A reminder of the role of spinodal decomposition, particular to these alloys, showed the possible evolution of phases more or less rich in tin.
These alloys especially require specific surface preparations, adapted to the elements considered, present in oxide form: this is what Pierre DEFAYE of RADIALL put forward, with the problem of surface treaters who would like to have a rather standard activation or stripping product for these alloys, while respecting dimensional criteria for connector applications. A solution was provided in preparation of Ni/Au coatings.
During the second part of the conference, the principals came to expose their choices and problems related to the use of copper alloys.
Jean-Michel CORRIEU of NAVAL GROUP explained the needs of copper products exposed to a marine environment, with the constraints of pressure and stagnation of water in the supply circuits. He presented some criteria for choosing copper-nickel or CuAlNi as a replacement for titanium alloys or austenitic stainless steels, while presenting problems and damages related to dealuminization and other forms of corrosion (stress corrosion, erosion, etc.).
Sophie ROURE from SCHNEIDER ELECTRIC then discussed specific R&D developments in copper, in particular automated CuCr vacuum sintering for densities above 95%, enabling the production of medium voltage elements.
This presentation was completed by Arnaud GAUTIER who focused on an application of copper cold spray coating in mass production on flat aluminium bars.
And to close the day, Eric THIEFFRY from OERLIKON BALZERS highlighted the role of thin-film surface coatings to gain in production on high-speed steel stamping tools, noting that stamping copper parts generates more production stoppages than steels with the same mechanical properties, probably due to the transfer of one metal to the other.
It then presents the aspect of coating on copper to facilitate the evacuation of calories during the operations of striking of plastics, while approving the difficulty of an adapted surface preparation before coating for these specific alloys.
The day ended with a final thank you to all the speakers, participants, ENSIL-ENSCI and the students of Materials engineering who attended the presentations with assiduity. The future Copper Day is already envisaged with the will of the team to integrate internationally renowned copper manufacturers.
