Influence of beam focus position on penetration characteristics and effect of heat treatment on ti6a14v electron beam weld properties

Abstract

Titanium and its alloys available in a range of high specific strength material, newlineconsidered as one of the best engineering materials for use in industrial application. The newlineand#945; - and#946; titanium alloy Ti6Al4V is currently the wok-horse titanium alloy of aerospace newlineindustry due to its good strength coupled with good fabricability. The welding newlinetechnology of titanium is complicated due to the fact that appreciable contamination by newlineoxygen, nitrogen and hydrogen can occur above 650 and#61616;C causing severe embrittlement newlineand at its melting point the metal rapidly dissolves these gases and carbon. Due to newlinetitanium material s high reactive property at elevate temperatures; protection from newlineatmospheric gases is essential. Due to advantages like contamination-free weld, newlineElectron Beam Welding (EBW) process is being widely used for the joining of these newlinealloys and the present work is done in this material and process. newlineThe aerospace system as a whole operates under high stress levels with a low margin newlineof safety. Titanium being a potential material in aerospace area, welding of these alloys newlinebecomes an important technological feature requiring extensive study. Elaborate newlinestudies have been reported in welding of this alloy but some of the important aspects newlinerelated to its welding have not been covered. The present work is aimed to fill these newlinetechnological gaps and provide useful suggestions through this study. The following newlinepoints have been specifically focused in the present work: newlineand#61656; Effect of focus current and work distance on the weld penetration characteristics newlineand#61656; Effect of pre- and post-weld heat treatment on weldment properties newlinevii newlineThe first part of the work was aimed to find the effect of focusing current (If) on work newlinedistance (WD), effect of If on depth of penetration (DoP) with variable WD and effect newlineof If on full penetration weld with variable WD. This study revealed that If decreases as newlinethe WD increases and the sensitivity of If is more at shorter WD and it is inversely newlineproportional to WD.