2024/04/17 by Shayakhmetova, Elvina Rafitovna, Murzinova, Mariya Alexandrovna, Mukhametgalina, Aygul Akhtamovna +1
#FOS: Materials engineering #Materials engineering
paper · doi:10.48612/letters/2024-1-91-96
Interest in materials with ultrafine-grained and nanocrystalline structures is explained by their unique strength properties. At the same time, the manufacture of complex parts from such materials is accompanied by grain growth, since the structure is not stable at heating. This study presents the results of structure examination of ultrasonically welded nickel plates with an initial grain size of 0.3 μm processed by high-pressure torsion. The analysis revealed that a gradient microstructure was formed in the samples produced by ultrasonic welding (USW). The grain size increased to the values ranging from 3 µm in the bottom plate up to 6 µm in the top one. The growth of grains was accompanied by the formation of a substructure. In the bulk of the welded plates, partially axial microtexture similar to the texture of warm-rolled nickel was formed and the directions <111> representing the rotation axes of grains were perpendicular to the joining surface. During USW, two competing processes, namely, the grain growth due to heating and the formation of new recrystallized grains 1.7 µm in size due to dynamic recrystallization occurred in a narrow layer with the thickness of about 10 µm along the joint zone.