Current Problems of Joinability of Titanium and Titanium Alloys

摘要

The most important strategy for joining components of Titanium alloys is the Joinability. The complex concept of Joinability describes the relation between the joining structure, which has to be produced by a tailored joining process to components of special material, chosen for use and service functions of the designed new product. The Joinability of Titanium and its alloys takes into account the joining suitability of the material, the join reliability of the structure and the join capability of the production processing. The joining suitability depends on the material properties. It is meet, if the chemical, metallurgical, mechanical, electrical and physical properties of the material allow the manufacturing of the novel innovative product with the demanded service and functional properties. The joining capability of a novel product exists, when there is one capable manufacturing process to join the components of a Ti-alloy, chosen and designed for the structure, to fulfil all designed service properties of the joined structure during its life-time. The limited joining capability of Titanium and Titanium alloys is discussed by the reactivity of Titanium with atmospheric gases during the wide range of fusion welding processes despite the advantageous material properties, following in specialised welding procedures tailored to the material and its demanded fitness for purpose. That are the modified A-TIG welding procedure using active flux and the magnetically impelled narrow-gap TIG welding beside the beam procedures with laser or electron beam. The joining reliability proves the realisation of the designed product and manufactured component, taking into account the designing for service and processing with respect to the suited material.