Авіаційно-космічна техніка та технологія (Apr 2024)
Complexly alloyed titanium alloys research performed by fusion welding
Abstract
The subject of this article is peculiarities of weld seam formation of complex titanium alloys during electron beam welding in vacuum and argon arc welding. The purpose of this study is to ensure the required level of mechanical properties of welded structures from complex titanium alloys to improve the structure and properties of welded joints. The task: to investigate the processes that are taking place in the zone of thermal influence and to determine their influence on defects formation; to determine the modes of parts welding made of complex titanium alloy; to study the effect of electron beam welding on the materials properties, such as strength, crack resistance, and corrosion resistance. Research results. The thermal cycle influence of welding and subsequent heat treatment on the structural and phase transformations in the weld metal and the heat-affected zone of complex titanium alloy welded joints was studied. It was established that a structure with a metastable β-phase predominance is formed in the weld metal and the zone of welded joints thermal influence, which contributes to the reduction of plasticity and impact toughness. The best combination of the studied welded joint strength and ductility was obtained after heat treatment, annealing at a temperature of 950 °C for 1 h, and cooling in the furnace. The use of filler wire contributes to obtaining an almost uniform structure and the disintegration of metastable phases in the seam as well as in the zone of thermal influence, and the strength limit is 1250 MPa. Conclusions. The influence of filler wires on the obtained samples structure and properties was studied, and the results were discussed depending on possible practical implementations. This article describes the creation and testing of elements of electron beam welding of complex titanium alloys technological process. This makes it possible to widely use welded combined titanium alloys in products of the appropriate purpose. The obtained scientific and practical results lead to increased mechanical properties of complex titanium alloys welded joints to the level of the base metal.
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