Carbon fibre-reinforced plastics (CFRPs) are helping the aircraft construction industry soar to ever greater heights. Pioneers like the Airbus A350 and Boeing 787 Dreamliner have long since increased the amount of fibre composites from 30 to 50 per cent – and that figure is growing. So cost-effective machining of CFRP components is an ongoing issue which will spur on leading aerospace suppliers such as Austrian company FACC now and in the future. The potential for this optimisation comes in part from the hundreds of thousands of holes which need to be drilled to assemble passenger jet components. Some are drilled with semi-automatic precision drill feed units, others with CNC machines or drilling robots which have the flexibility to adapt to the fuselage or other components and move using automatic programmes. To produce the holes, the tools drill through material between 11 and 25 millimetres thick with tolerances of just ten micrometres. This highly abrasive machining places extreme demands on the tools: unlike metals, CFRP composites are not homogenous and have various fibre and coating structures, which need to be drilled through with a high level of accuracy and without making the surface burst. C6 Composite Tooling, from Buchen in Baden-Württemberg, specialise in meeting these kinds of challenges. Targeting the automotive, aerospace and rail markets, they offer all-round solutions for machining lightweight materials. For FACC they developed an optimised machining process including tools for drilling into winglets, extensions to wingtips which reduce air resistance and help minimise fuel consumption, emissions and noise.

From 80 to 250 holes

C6 were tasked with improving the existing drilling process, which used an expensive tool solution but only resulted in a tool service life of 80 holes. The breakthrough came when coating partner Oerlikon Balzers got involved. They worked with C6 to test and adapt various tool substrates, tool geometries, production conditions and process parameters to the diamond coating BALDIA COMPOSITE DC. The nanocrystalline CVD (Chemical Vapour Deposition) coating, specially designed for machining composite materials, has very high abrasive wear resistance and enables optimum process reliability and top-quality drilling. 2/5 In use, it produced outstanding results: once coated, the one-shot drill more than tripled the tool service life to 250 holes and more than halved the tool costs. “The intensive, close partnership was crucia l in order to develop the optimum product composition with the substrate, pre-treatment and coating. Without the coating, we wouldn’t have produced a cost-effective drilling process”, say both Sebastian Herkert, Head of Technical Sales at C6, and Gerhard Hagedorn, Head of Diamond Customer Support at Oerlikon Balzers, of the project. And their customer confirms its success: “The tools and coatings work in all applications, whether on semiautomatic drill feed units or on CNC machines. Of course we’re delighted with the high cost-effectiveness of the drilling application, as well as the quick tool changeovers and other processing times. This helps us achieve our main targets”, explains Andreas Mayer, Automation Technology Engineer at FACC.

Source | Oerlikon Balzers

Im Einsatz erzielte sie exzellente Ergebnisse: Der finale beschichtete One-Shot-Bohrer kam mit 250 Bohrungen auf eine über dreimal höhere Standzeit, die Werkzeugkosten sanken um mehr als die Hälfte. „Die intensive, enge Partnerschaft war unverzichtbar für die Entwicklung des optimal zusammengestellten Produkts mit Substrat, Vorbehandlung und Beschichtung.

Ohne die Beschichtung hätten wir keinen wirtschaftlichen Bohrprozess erreichen können“, bewerten Sebastian Herkert, Technischer Vertriebsleiter bei C6, und Gerhard Hagedorn, Leiter Customer Support Diamond von Oerlikon Balzers, unisono das Projekt. Den Erfolg bestätigt auch der gemeinsame Kunde: „Werkzeug und Beschichtung funktionieren in allen Applikationen, auf halbautomatischen Bohrvorschubeinheiten sowie auf CNC-Maschinen. Besonders erfreut sind wir natürlich über die hohe Wirtschaftlichkeit der Bohranwendung, über geringere Werkzeugwechsel- und Nebenzeiten. Dies unterstützt unsere zentralen Ziele“, äußert sich Andreas Mayer, Engineer Automation Technology von Facc.

Quelle | Oerlikon Balzers