Laser welding between the magnetic stainless steels and
titanium as a shield-ring and spacer material
Yukyo Takada, M. Takahashi, Jun
Shiroto, A. Kikuchi1 and M. Kikuchi
Division of Dental
Biomaterials,
1 NEOMAX ENGINEERING Co.,Ltd.,
Abstract
In this
study, we focused on pure titanium as a nickel-free material used for a
shield-ring and spacer, and examined its weldability to the magnetic stainless steels such as SUS444, SUSXM27 and SUS447J1 by
the laser welding. When titanium was welded with each stainless steel, some large cracks
were observed on the beads. The running cracks passed into inside of the beads. According to a bending test, all of welded zone
broke down easily. In the case of the thin titanium ribbon wedged between the
stainless steels, the bending load below 200g also destroyed all of the
sandwich line.
Formation of hard and brittle intermetallic compounds apparently caused
the large cracks and weakened the weld zone. However, when a titanium alloy
containing much titanium, a 83at%Ti-11at%Fe-6at%Cr alloy was prepared, it showed
a little ductility because it might had a meta-stable b phase. If much titanium can melt into the bead, a
meta-stable b phase possibly forms in the bead and adds
ductility to the weld zone. Although titanium has the hurdle to control the
composition of the bead, the meta-stable b phase in the bead possibly takes a chance to improve
weldability between titanium and magnetic stainless steels.