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European Organization for Nuclear Research

Aluminium ConFlat flange

This robust, fully aluminium ConFlat flange for UHV application is considerably more economical and reliable than commonly used stainless steel bi-metallic flanges. No additional surface treatments, such as hardening coatings, are required. The concept is to use high strength aluminium alloys for the flanges, either with Lithium or with a rapid solidification process, and a soft aluminium gasket, made of pure aluminium or annealed 5XXX series. As commonly the case for aluminium UHV components, this ConFlat flange is qualified up to ~ 220° C.


· Manufacturers of UHV components, low rejection factor

· Semiconductor industry

· Scientific community


· Fully UHV compatible, leak rate below 1-10 mbar·l/s)

· No size constraints

· Up to five times lower cost than stainless steel bi-metallic flange, increased reliability

· No additional surface treatment required

· Aluminium properties: light, low magnetic permeability, low outgassing, low material activation under radiation

· Aluminium – Lithium alloy (Constellium – 21-90, 21-96, 2195), or

· Aluminium alloy with ultra-fast solidification. Fine structure increases mechanical properties. (RSA-501, RSA-9001)


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