Development of titanium weld metal reinforced by titanium mono-boride

Abstract

In order to reinforce the mechanical properties of titanium weld, titanium mono-boride (TiB) was dispersed in the weld metal with gas tungsten arc welding process. The microstructure difference of weld metal between the TiB-reinforced titanium and pure-titanium were made clear by the observation in the surface and cross section of weld metal. The distributions of TiB were particular in welding and the crystal orientation analysis showed the TiB was distributed between cell microstructures. It was found that the hardness increased in TiB-reinforced weld metal suggesting increasing of tensile strength. Furthermore, the effect of boron addition on the weld pool convection was found and the mechanism was discussed. © 2008 ISIJ.