Verification study of wire arc additive manufacturing of titanium alloy TI6AL4V

Abstract

In this thesis, wire arc additive manufacturing (WAAM) method is investigated for production of titanium alloy Ti6Al4V. WAAM is a sub category of directed energy deposition (DED) methods. Tungsten inert gas (TIG) based WAAM technology is utilized for production. 6 axis robotic system, wire feeding unit, welding machine are main elements of the WAAM system used in this thesis. These three equipment are responsible from travel speed, wire feeding speed and heat input, respectively. In addition, flexible inert chamber is also designed and manufactured since titanium's high oxygen affinity. Flexible inert chamber is filled with argon to exclude volume from atmosphere's oxygen. With the help of these equipment, a test wall is printed from Ti6Al4V alloy. It is designed according to required specimen numbers of the standards. Non-destructive tests are conducted for checking porosity or crack presence. Specimens will be extracted from the test wall with water jet cutting method for minimum heat exposure during cutting process. Tensile and fatigue test are conducted as destructive test for obtaining strength data of the material.