Structural phase transformations study of brittle refractory metals - PowerPoint PPT Presentation

SFR-2016 Structural phase transformations study of brittle refractory metals and intermetallics with L1 2 structure using synchrotron radiation PILYUGIN, Vitaliy SOLOV’EVA, Yulia ANCHAROV, Alexey STARENCHENKO, Vladimir STARENCHENKO, Svetlana TOLMACHEV, Timofey M.N. Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences (IMP UB RAS) Tomsk State University of Architecture and Building Institute of Solid State Chemistry and Mechanochemistry SB RAS

Aims, materials and methods Study of microstructure and phase state: intermetallic Ni 3 Ge, with anomalous properties, transitional 3d-4d metals (Fe, Ti, Zr), including refractory fragile (Mo, Ir, Re) after deformation under high pressure (HPT) SR, NGR, TEM, SEM, metalography, mechanical tests

SCSTR Budker INP SB RAS Diffractometry in hard X-rays λ =0.3686 A °

HPT in Bridgman anvils - shear under pressure. Ag in situ under pressure 12 GPa between c-NB, SR, λ =0.3686 A °

The microstructure of superalloys with intermetallic phase (Ni 3 Ge, Ni 3 Al, Ni 3 Fe) γ фаза /

Alloys with anomalous temperature dependence of the flow stresses: Ni 3 Ge, Ni 3 Al, Ni 3 Fe, Ni 3 W 120 à) 8 á) Ni3Al Ni3(Al,W) a) Ni 3 Al 0,2% , 10 МПа 80 6 0,2% , 100 МПа 7,8 10 -5 мм/с σ 4 40 σ 2 0 8 10 -2 мм/с â) Ni 3 Ge ã) Ni 3 Ga 0,2% , 10 МПа 0 C 80 - C б ) - B - B А Ni 3 (Al,Ti) B - A - A - D σ - C 6 0,2% , 100 МПа - E 40 132 А B C 4 E D 0 T, K 0 400 800 1200 0 400 800 1200 σ 2 5 4 3 2 1 0 Ni 3 Ga 20 Ni 3 Ge Ni 3 Ge 335 τ , 10MПа 114 16 Ni 3 Ga 12 8 4 в) 0 0 C -200 0 200 400 600 800 t, SFR-2016 SFR-2016 The data of different authors

Superstructure L 1 2 FCC - lattice  – А atoms  – В atoms

Plastic deformation superlocalization 673K 873K 6 973K 523K 40 2 МПа τ 0 , 10 МПа 423K 4 τ ,10 20 77K 293K 2 0 200 400 600 800 1000 0 T, K 0,0 0,1 0,2 0,3 ε 1mm T > 0 , 6 T пл 1mm

Plastic deformation superlocalization Т=923К, ε≈ 13% × 45 [0 0 1] × 140 × 400 × 900 × 900

Plastic deformation superlocalization Т=973К, ε≈ 9% (SCAN) × 45 [1 3 9] × 300 × 1200 × 1200

Polycrystalline Single crystal: (001) (031) (301)

Phase transitions

Fe phase diagram

λ = 0,368 ° A: Anvils c- NB; Fe: с -NB + ε -phase, P=14 GP а

Mössbauer spectra of strained iron under pressure. Left: CG sample. a – initial state b – 14.5 GPa, 45 % hcp; c – 16 GPa, 70 % hcp. Right: NC sample. a – initial state of the sample outside of anvils; b – 8.0 GPa 0 % hcp ; c – 16.8 GPa 11 % hcp; d – 18.5 GPa 48 % hcp; e – 19.5 GPa 72 % hcp

6 HYSTERESIS OF α - ε TRANSITION IN IRON 5 4 Н, ГПа In situ data NGR and SR 3 2 1 0 1 2 3 4 е 0.5 ∆ H = 4 ГПа

Ti

Ti

The mechanical properties of refractory 4d-metals σ В , δ ,% Ψ,% B, GPa G, GPa µ H µ ,GPa MPa 350-400 125-155 0.3 1000 0.6% 0% 3.480-3.800 W 520-590 199-266 0.28 490 6-10% 10-15% 1.960-2.350 Ir (70% м / к) 190 70 0.35 204 30% 75% 2.310 Ta

Products made of iridium Cont ntaine ner of pl plutoni nium o oxide allo lloy I Ir-0. 0.3% 3% W f for ther ermoel elect ectric g c gen ener erator, Galileo, 1989 Franko-Ferreira E.A., Goodwin G.M., Iridium cr cruci cibles es of d differ eren ent shapes es, wire re, George T.G., Rinehart G.H. rolled, t tube bes, ing ngotshi high-proce cessed m met etal, Long life radioisotopic sources encapsulated in platinum metal alloys. massive single c crystals (Ekaterinbu nburg pl plant nt ) Platinum Metals Rev.-1997.-vol. 41, No 4, pp. 154 – 163 ( Окриджская национальная лаборатория, США)

Ir, HPT ε≥ 5, 14 GPa Nanostructure of iridium

Ta diffraction patterns in SR MAR RESEARCH 3450

Ta texture after HPT (200) (110) Initial n=1 n=5

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