Nitinol is a shape memory and superelastic alloy, respectively, and stainless steels are widely used materials in medical engineering, e.g., for implants and medical instruments. However, due to its high price and poor machinability, there is a high demand for dissimilar welding of nitinol components to stainless steel. During welding of titanium-containing alloys, like nitinol, to ferrous metals like stainless steel, intermetallic phases between titanium and iron may form. These phases are brittle and lead to rapid crack formation and/or inferior mechanical properties of the joint. In this study, superelastic nitinol wires are butt-welded with stainless steel wires by means of micro electron beam welding, providing good quality weld seams. Due to a very accurate beam alignment and fast beam deflection, the composition and the level of dilution in the weld metal can be precisely controlled, resulting in a significant reduction of fraction of intermetallic phases. The experiments show that it is possible to produce sound welds without the presence of any cracks on the surface as well as in the cross sections.
@article{doi:10.17170/kobra-202011182198,
author ={Hellberg, Sebastian and Hummel, Joana and Krooß, Philipp and Niendorf, Thomas and Böhm, Stefan},
title ={Microstructural and mechanical properties of dissimilar nitinol and stainless steel wire joints produced by micro electron beam welding without filler material},
keywords ={600 and Elektronenstrahlschweißen and Medizintechnik and Nitinol and Edelstahl and Intermetallische Verbindungen},
copyright ={http://creativecommons.org/licenses/by/4.0/},
language ={en},
journal ={Welding in the World},
year ={2020-09-18}
}