The effect of high-temperature annealing on the stability of the structure and properties of welded joints in tungsten single crystals with planar and axial geometry

The results of experimental studies of the effect of high-temperature treatment on the stability of the substructure, crystallography and mechanical properties of welded joints in tungsten single crystals with planar and axial geometry are presented. The main task of the study was to obtain data on the possibility of producing monohedral tubes of tungsten single crystals with a stable structure (ρ = 105–106 cm−2), with permissible misorientation angles at the sub-boundaries (θ < 3°) in the central part of the welded joint and strength characteristics (σbend of the weld metal should be higher than or equal to σbend of the parent metal), suitable for service of these components at working temperatures (up to 2500 °C). The methods for producing pipes with the required homogeneous orientation of the side (working) surface made of a single crystal tungsten ingot are described.