Fabrication of Miniature Titanium Capsule for Brachytherapy Sources Using Tungsten Inert Gas (TIG) Method

Abstract

The capsules containing radioactive materials as brachytherapy sources are used for implanting into some target organs for malignant disorders treatments, such as prostate, eyes, and brain cancers. The conventional method for sealing the tubes is to weld them using a laser beam which is now a part of tube melting methods (self welding). The purpose of this study was to seal miniature titanium tubes containing radioactive materials in the form of capsules. This study introduced a new method based on melting process. A piece of commercially pure titanium grade 2 in the form of disk was used for the experiment. The sample was melted at the top of the tube by a TIG welding device for a short time duration. After complection of the melting, the disk in the form of a drop was mixed with a small part of it and both were solidified and hence closed the tube. We evaluated the tubes for the metalargical properties and seal process which took place by TIG in different zones, including the heat affected zone (HAZ), fusion zone (FZ), and interface (I) of the joint of the drop to the tube. Finally, the produced samples were tested according to the ISO2919 & ISO9978 and the results confirmed the Disk & TIG procedure.

Keywords

• brachytherapy source
• tig welding
• titanium capsule