- BMWi
- Arbeitsgemeinschaft industrieller Fördervereinigungen Otto von Guericke e. V.
Nitinol, an alloy of about 50% nickel and 50% titanium, commonly used in medical technology, shows two important properties: the shape memory effect and superelasticity. In many industrial sectors it is necessary to combine steel under preservation of the superelasticity.
In the project the two materials are combined using micro beam-and laser welding with biocompatible additives. The resulting bond tolerates a tensile stress in the range of the superelastic plateau of nitinol.
Stainless steel, titanium and titan alloys are widely used in medical technology because of their good biocompatibility. Nitinol as phase of about 50% nickel and 50% titanium is characterized by showing shape changes when stimulated from outside transformation. It can tolerate, depending on the condition elastical prolongation up to 10% without noteworthy plastical deformation
While similar welding both on titanium an on stainless steel can be done by laser and electron beam welding with the same tensile strength of the material itself and even nitinol shows in a similar welding 80% of the tensile strength of the nitinol the dissimilar welding is difficult. Welding these materials embrittled intermetallic phases are generated. That’s why melting welding techniques are not or with limited bonding properties used.
Nevertheless the use of products with welded conjunction witout limitation in the mechanical technological properties is for small and medium sized enterprises in the industrial sector ogf medical and microsystem technology very important.
In the project the two materials are combined using micro beam-and laser welding with biocompatible additives. The resulting bond tolerates a tensile stress in the range of the superelastic plateau of nitinol.s.
- Universität Kassel, Institut für Produktionstechnik und Logistik, Fachgebiet für Trennende und Fügende Fertigungsverfahren (tff)