Abstract
NiAl is an intermetallic compound with a brittle-to-ductile transition temperature at about 300°C and ambient pressure. At standard conditions, it is very difficult to deform, but fracture stress and fracture strain are increased under high hydrostatic pressure. On account of this, deformation at low temperatures is only possible at high hydrostatic pressure, as for instance used in high pressure torsion. In order to study the influence of temperature on texture evolution, small discs of polycrystalline NiAl were deformed by high pressure torsion at temperatures ranging from room temperature to 500°C. At room temperature, a typical shear texture of body centred cubic metals is found, while at 500°C a strong oblique cube component dominates. These textures can be well simulated with the viscoplastic self-consistent polycrystal deformation model using the primary and secondary slip systems activated at low and high temperatures. The oblique cube component is a dynamic recrystallization component.
Highlights
NiAl is an intermetallic compound with B2 structure
During high pressure torsion (HPT) it drastically changes with the changes strongly depending on deformation temperature
The textures resulting from large strain shear deformation at room temperature and 500°C are compared
Summary
NiAl is an intermetallic compound with B2 structure. Some of its characteristics make it a good candidate for technical applications at high temperatures, as for example the low density of 5.85 g/cm3 or the high melting point of 1638°C at stoichiometric composition as well as the very good oxidation resistance or the low coefficient of thermal expansion [1]. Small discs of this material with a diameter of 8 mm and a height of 0.8 mm were deformed at room temperature and 500°C by HPT at a constant pressure of 8 GPa. According to [3], the shear strain in torsion is given by the relationship γ = 2πNr , (1) Two rotations are used resulting in a theoretical maximum shear strain of γ ≈ 60 at the edge of the sample. Simulations have been carried out using the viscoplastic self-consistent (VPSC) model through the JTEX software.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IOP Conference Series: Materials Science and Engineering
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
