Crystallographic Texture and Functional Properties of Powder Titanium Alloys after Thermomechanical Treatment

• Published in: Surface investigation, x-ray, synchrotron and neutron techniques Vol. 17; no. 2; pp. 484 - 489
• Main Authors: Markova, G. V., Ivankina, T. I., Levin, D. M., Volodko, S. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.04.2023; Springer Nature B.V
• Subjects: Alloy powders; Chemistry and Materials Science; Crystallography; Deformation; Extrusion; Forging; Materials Science; Neutron diffraction; Nickel base alloys; Nickel compounds; Nickel titanides; Nuclear research; Pole figures; Shape memory alloys; Sintering (powder metallurgy); Superelasticity; Surfaces and Interfaces; Texture; Thermomechanical treatment; Thin Films; Titanium alloys; Titanium base alloys; Titanium compounds; Workpieces; twinning; sintering; radial shear rolling; shape memory effect; extrusion; neutron diffraction; powder metallurgy; crystallographic texture; superelasticity; rotary forging; martensite
• ISSN: 1027-4510; 1819-7094
• DOI: 10.1134/S1027451023020325

A relationship is established between the crystallographic texture developed during various thermomechanical treatments and the functional properties of titanium-based alloys, in particular, titanium nickelide obtained by sintering calcium-hydride powder. The thermomechanical treatment of sintered workpieces is carried out by rotary forging, radial shear rolling, or extrusion. The temperature of the last stage of deformation in all cases is 900°C. The neutron diffraction analysis of the samples is performed on the SKAT texture diffractometer at the Joint Institute for Nuclear Research (Dubna, Russia). The projection plane of the experimental pole figures is perpendicular to the sample axis and the deformation axis. The shape memory characteristics are determined by torsion deformation on wire samples cut from rods along the axis. The texture is most fully demonstrated by the sample after extrusion: the volume fraction of textured grains reaches 85%, and the maximum pole density is 2.76 m.r.d. (multiple of a random distribution). The functional properties under torsion deformation γ pore = 2–16% are studied. Extruded samples and samples subjected to radial shear rolling demonstrate the best superelasticity in the austenitic phase γ super = 15% and maximum values of the critical stresses γ cr = 15%, starting from which the deformation becomes irreversible. The relationship between the sharpness of the crystallographic texture and the functional properties of the TiNi alloy after thermomechanical treatment is revealed.