Influence of the filler metal on the properties of Ti-6Al-4V electron beam weldments. Part I: Welding procedures and microstructural characterization

The use of different procedures for electron beam welding of 17 mm thick Ti-6Al-4V plate and the difficulties found in this process are analysed. When this alloy was welded autogeneously the presence of significant amounts of α martensite was observed, recommending looking for another solution. In the early trials a V joint design was used but distortions and defects were detected in the welds when multi-pass procedures were considered. Consequently, for the remaining weldments K or I joint configurations were selected. Initially, Ti-6Al-4V wire was preferred in order to match mechanical properties with base material but no significant improvement was found leading to consideration of using a less alloyed filler metal. Different commercially pure titanium filler metals have been employed to optimise the performance of the fusion zone of electron beam weldments. In a second paper [1] the influence of the welding procedure on the mechanical properties of the various joints will be discussed.