Combination of Shear and Rotational Deformations As an Effective Solution for Obtaining Ultrafine-Grained Semifinished Products from Superalloys

Superplastic deformation of ultrafine-grained semifinished products is used in production of turbine engine disks from heat-resistant superalloys based on nickel, iron, and titanium. This technology is based on gatorizing, which is implemented using powerful horizontal hydraulic presses for the manufacture of ultrafine-grained bars and vacuum-forming complexes for the manufacture of discs from bars in an oxidizing-free atmosphere. This article discusses the theoretical and practical prerequisites for the development of an effective deformation for obtaining an ultrafine-grained structure in superalloys. The technological advantages of using combined methods are shown, combining shear and rotational strain components for the formation of an ultrafine-grained structure in large-sized billets. Using the example of upsetting (or tension) with torsion, the stress–strain state of the material and the energy–power parameters of deformation, as well as the design and technological features of the equipment ensuring the refinement of the bars and disks structure, are determined.