Gradient changes in structural condition of the B2 phase of NiTi surface layers after electron-beam treatments
- Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk State University, Tomsk, 634050 (Russian Federation)
- Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)
- Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation)
Structural conditions of the B2 phase of the Ti{sub 49.5}Ni{sub 50.5} alloy surface layers before and after electron-beam treatments (pulse duration τ = 150 μs, number of pulses n = 5, beam energy density E ≤ 20 J/cm{sup 2}) were studied by X-ray diffraction analysis. Analysis of the X-ray patterns demonstrates that surface layers modified by electron beam treatment contain phase with B2{sup surf} structure. It is revealed that the lattice parameter of the B2{sup surf} phase in the surface (modified) layer is also higher than the lattice parameter of the B2 phase in the underlying layer (a{sub B2} = 3.0159±0.0005). The values of lattice parameter of phase B2{sup surf} amounted a{sub B2}{sup surf} = 3.0316±0.0005 Å and a{sub B2}{sup surf} = 3.0252±0.0005 Å, for the specimens after electron-beam treatment at E{sub 1} = 15 J/cm{sup 2} and E{sub 2} = 20 J/cm{sup 2}, respectively. Inflated lattice parameters a{sub B2}{sup surf} are associated with changes in the chemical composition and the presence of residual stresses in the surface region of the samples after electron-beam treatments.
- OSTI ID:
- 22390427
- Journal Information:
- AIP Conference Proceedings, Vol. 1623, Issue 1; Conference: International Conference on Physical Mesomechanics of Multilevel Systems 2014, Tomsk (Russian Federation), 3-5 Sep 2014; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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