Viscoelastic Deformation and Fracture of Porous Nickel Titanium after Tension and Cyclic Bending

• Published in: Russian physics journal Vol. 63; no. 7; pp. 1243 - 1248
• Main Authors: Marchenko, E. S., Yasenchuk, Yu. F., Baigonakova, G. A., Gyunter, S. V., Shishelova, A. A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2020; Springer
• Subjects: Alloys; Basketball players; Coatings; Condensed Matter Physics; Hadrons; Heavy Ions; Intermetallic compounds; Lasers; Mathematical and Computational Physics; Nickel; Nuclear Physics; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; Theoretical; Titanium; self-propagating high-temperature synthesis; fatigue strength; TiNi alloy; viscoelastic deformation; wire; surface; fracture pattern; structure
• ISSN: 1064-8887; 1573-9228
• DOI: 10.1007/s11182-020-02152-x

The paper deals with the deformation curves and fatigue tests of the porous nickel–titanium (NiTi) alloy produced with self-propagating high-temperature synthesis. Deformation curves obtained for tension and three-point bending of porous NiTi plates demonstrate their viscoelastic deformation due to the austenite-to-martensite phase transformation. Scanning electron microscopy observations of the fractured surface show the regions of quasi-brittle fracture of martensite and ductile fracture of austenite. Brittle fracture is observed for nonmetallic inclusions and the porous structure coating of the intermetallic compound. Fatigue tests show that the brittle phases and inclusions have no critical negative effect on the strain and fatigue properties of the NiTi alloy. It is determined that 70% of the porous alloy specimens withstand 10 6 cyclic bending owing to the reversible austenite-martensite phase transformation in the parent phase which is one the components of the multi-phase porous alloy.