Biomaterials

Biography

Biography: Bernhard Mingler

Abstract

Equal Channel Angular Pressing (ECAP) is an innovative processing technology for the production of metallic biomaterials with unique properties. It leads to a strong grain refinement of bulk crystalline materials down to the sub-micrometer range by means of very large, multidimensional plastic deformation under enhanced hydrostatic pressure. The modified microstructure of ECAP-processed biomaterials is the reason for high strength combined with good ductility. Such high-performance biomaterials are very promising candidates for applications in high-loaded implants, for longer implant lifespans, for the miniaturization of implants and for completely new implant concepts. The effects of ECAP are presented on the examples of commercially pure (CP)-titanium and special Mg-alloys. CP-Ti is a commonly used implant material especially in dentistry. In this field of application, the Ti-alloy Ti6Al4V-ELI is avoided because of its problematic alloying elements aluminum and vanadium. Nevertheless, for many dental applications a higher strength than that of CP-Ti is requested. Using ECAP and tailored optional post-processing we achieved in CP-Ti ultimate tensile strengths >1000 MPa, which is stronger than the Ti-alloy. A further very important effect of ECAP is that it produces a very homogeneous ultrafine grain structure and consequently very homogeneous mechanical property across the whole work piece. The ideal material for biodegradable implants must combine high biocompatibility, application-oriented degradation rate and excellent mechanical properties especially for load bearing applications. To achieve all these goals, we used a newly developed double-ECAP tool to process a special low alloyed Mg alloy which was developed and produced at AIT. The double-ECAP tool consists of three channels with two intersection angles and offers exceptional high deformation efficiency. By using it, the ultimate tensile strength of a ZX00 Mg alloy could be raised to unprecedented strength values of about 400 MPa.