Mechanical Properties of Arc Welded in Vacuum Ti-6Al-4V Alloy

Titanium alloys are known for their good mechanical properties, low density, excellent corrosion resistance and low thermal conductivity. These properties define titanium and its alloys as highly suitable for medicine, automotive and aerospace industries. Unfortunately, the thermal cycle during welding of alpha-beta alloys (Ti-6Al-4V) can significantly change their strength, toughness and plasticity. The scope of present work is to investigate the possibility for producing Ti-6Al-4V welds by arc discharge in vacuum and to establish the influence of the welding parameters on dimensions and mechanical properties of the welds. The experiments presented here were carried out in an installation for hollow cathode arc treatment in vacuum. Cylindrical and elliptical tantalum cathodes were used. The welding was carried out without filler material and groove. Tensile test and hardness test of specific welds zones were used for mechanical properties determination. The results, presented in this work, describe the dimensions of the fusion zone and heat affected zone of welds, produced by hollow cathode arc welding using different welding parameters. The mechanical properties of the welds were determined.