94 research outputs found
ΠΠ»ΠΈΡΠ½ΠΈΠ΅ ΠΊΠΎΠΌΠ±ΠΈΠ½Π°ΡΠΈΠΈ ΡΠ°Π΄ΠΈΠ°Π»ΡΠ½ΠΎ-ΡΠ΄Π²ΠΈΠ³ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΠΊΠ°ΡΠΊΠΈ ΠΈ ΡΠΎΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΊΠΎΠ²ΠΊΠΈ Π½Π° Π½Π°ΠΏΡΡΠΆΠ΅Π½Π½ΠΎ-Π΄Π΅ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΠΏΡΡΡΠΊΠΎΠ²ΠΎΠΉ Π·Π°Π³ΠΎΡΠΎΠ²ΠΊΠΈ ΠΌΠ°Π»ΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠ° ΠΈΠ· ΡΠΈΡΠ°Π½ΠΎΠ²ΡΡ ΡΠΏΠ»Π°Π²ΠΎΠ²
The paper focuses on the finite element method used to simulate the stress-strain state of a small-diameter bar stock during hot-forming in a combination of radial shear rolling (RSR) and rotary forging (RF). Simulation was carried out using the rheological model of the Ti-6Al-4V titanium-based alloy with the QForm VX software. A combination of radial shear rolling of a workpiece with a diameter of 15 mm to 12 mm bar in one pass and subsequent rotary forging in one, two and three passes to obtain bars with diameters 11, 10 and 8 mm is simulated. During the simulation, step-by-step accumulation of plastic deformation was taken into account in the conditions of its nonuniform distribution. The intermediate and finite fields of plastic deformation, strain rate and average stress are obtained. It is shown that plastic deformation distribution after RSR has an expressed gradient with a maximum value (3 or more) at the periphery of the cross-section and a minimum value (about 1) at the center. As a result of RF, even with small reductions, the stress-strain state becomes much more uniform compared with a workpiece of the same diameter after radial shear rolling only. In addition, residual tensile stresses due to compressive stresses during rotary forging are reduced. Direct experimental testing of the combined deformation method was carried out for a promising medical-grade Ti-Zr-Nb shape memory alloy when manufacturing 7-8 mm diameter rods in experimental production conditions. Qualitative confirmation of modeling results is obtained by metallographic analysis. It is shown that the combination of radial shear rolling and rotary forging is promising for creating industrial technologies for the manufacture of small-diameter rods with a highly uniform finely-dispersed structure.Π Π°Π±ΠΎΡΠ° ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° ΠΊΠΎΠ½Π΅ΡΠ½ΠΎ-ΡΠ»Π΅ΠΌΠ΅Π½ΡΠ½ΠΎΠΌΡ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π½Π°ΠΏΡΡΠΆΠ΅Π½Π½ΠΎ-Π΄Π΅ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ ΠΏΡΡΡΠΊΠΎΠ²ΠΎΠΉ Π·Π°Π³ΠΎΡΠΎΠ²ΠΊΠΈ ΠΌΠ°Π»ΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠ° ΠΏΡΠΈ Π³ΠΎΡΡΡΠ΅ΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ΅ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ΠΌ Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°ΡΠΈΠΈ ΡΠ°Π΄ΠΈΠ°Π»ΡΠ½ΠΎ-ΡΠ΄Π²ΠΈΠ³ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΠΊΠ°ΡΠΊΠΈ (Π Π‘Π) ΠΈ ΡΠΎΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΊΠΎΠ²ΠΊΠΈ (Π Π). ΠΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ΠΎ Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΡΠ΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΡΠΈΡΠ°Π½ΠΎΠ²ΠΎΠ³ΠΎ ΡΠΏΠ»Π°Π²Π° Tiβ6Alβ4V Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΡ QForm VX. Π‘ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΎ ΡΠΎΡΠ΅ΡΠ°Π½ΠΈΠ΅ ΡΠ°Π΄ΠΈΠ°Π»ΡΠ½ΠΎ-ΡΠ΄Π²ΠΈΠ³ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΠΊΠ°ΡΠΊΠΈ Π·Π° 1 ΠΏΡΠΎΡ
ΠΎΠ΄ Π·Π°Π³ΠΎΡΠΎΠ²ΠΊΠΈ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠΎΠΌ 15 ΠΌΠΌ Π½Π° ΠΏΡΡΡΠΎΠΊ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠΎΠΌ 12 ΠΌΠΌ ΠΈ ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠ΅ΠΉ ΡΠΎΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΊΠΎΠ²ΠΊΠΈ Π² 1, 2 ΠΈ 3 ΠΏΡΠΎΡ
ΠΎΠ΄Π° Ρ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΠ΅ΠΌ ΠΏΡΡΡΠΊΠΎΠ² Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠ°ΠΌΠΈ 11, 10 ΠΈ 8 ΠΌΠΌ. Π£ΡΠΈΡΡΠ²Π°Π»ΠΎΡΡ ΠΏΠΎΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ΅ Π½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΠ΅ ΠΏΠ»Π°ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
Π½Π΅ΡΠ°Π²Π½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ Π΅Π΅ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ. ΠΠΎΠ»ΡΡΠ΅Π½Ρ ΠΏΡΠΎΠΌΠ΅ΠΆΡΡΠΎΡΠ½ΡΠ΅ ΠΈ ΠΊΠΎΠ½Π΅ΡΠ½ΡΠ΅ ΠΏΠΎΠ»Ρ ΠΏΠ»Π°ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ, ΡΠΊΠΎΡΠΎΡΡΠΈ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΈ ΡΡΠ΅Π΄Π½Π΅Π³ΠΎ Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΡ. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΠΏΠ»Π°ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΏΠΎΡΠ»Π΅ Π Π‘Π ΠΈΠΌΠ΅Π΅Ρ Π²ΡΡΠ°ΠΆΠ΅Π½Π½ΡΡ Π³ΡΠ°Π΄ΠΈΠ΅Π½ΡΠ½ΠΎΡΡΡ Ρ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΡΠΌ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ΠΌ (3 ΠΈ Π±ΠΎΠ»Π΅Π΅) Π½Π° ΠΏΠ΅ΡΠΈΡΠ΅ΡΠΈΠΈ ΡΠ΅ΡΠ΅Π½ΠΈΡ ΠΈ ΠΌΠΈΠ½ΠΈΠΌΠ°Π»ΡΠ½ΡΠΌ (ΠΎΠΊΠΎΠ»ΠΎ 1) Π² ΡΠ΅Π½ΡΡΠ΅. Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ Π Π Π΄Π°ΠΆΠ΅ Ρ Π½Π΅Π±ΠΎΠ»ΡΡΠΈΠΌΠΈ ΠΎΠ±ΠΆΠ°ΡΠΈΡΠΌΠΈ Π½Π°ΠΏΡΡΠΆΠ΅Π½Π½ΠΎ-Π΄Π΅ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΡΡΠ°Π½ΠΎΠ²ΠΈΡΡΡ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ Π±ΠΎΠ»Π΅Π΅ ΠΎΠ΄Π½ΠΎΡΠΎΠ΄Π½ΡΠΌ ΠΏΠΎ ΡΡΠ°Π²Π½Π΅Π½ΠΈΡ Ρ Π·Π°Π³ΠΎΡΠΎΠ²ΠΊΠΎΠΉ ΡΠ°ΠΊΠΎΠ³ΠΎ ΠΆΠ΅ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠ° ΡΠΎΠ»ΡΠΊΠΎ ΠΏΠΎΡΠ»Π΅ ΡΠ°Π΄ΠΈΠ°Π»ΡΠ½ΠΎ-ΡΠ΄Π²ΠΈΠ³ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΠΊΠ°ΡΠΊΠΈ. ΠΡΠΎΠΌΠ΅ ΡΠΎΠ³ΠΎ, ΡΠΌΠ΅Π½ΡΡΠ°ΡΡΡΡ ΠΎΡΡΠ°ΡΠΎΡΠ½ΡΠ΅ Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΡ ΡΠ°ΡΡΡΠΆΠ΅Π½ΠΈΡ ΠΈΠ·-Π·Π° ΡΠΆΠΈΠΌΠ°ΡΡΠΈΡ
Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠΉ ΠΏΡΠΈ ΡΠΎΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΊΠΎΠ²ΠΊΠ΅. ΠΡΡΠΌΠΎΠ΅ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΠΎΠ΅ ΠΎΠΏΡΠΎΠ±ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠΏΠΎΡΠΎΠ±Π° Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ Π΄Π»Ρ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠΏΠ»Π°Π²Π° TiβZrβNb Ρ ΠΏΠ°ΠΌΡΡΡΡ ΡΠΎΡΠΌΡ ΠΌΠ΅Π΄ΠΈΡΠΈΠ½ΡΠΊΠΎΠ³ΠΎ Π½Π°Π·Π½Π°ΡΠ΅Π½ΠΈΡ ΠΏΡΠΈ ΠΈΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½ΠΈΠΈ ΠΏΡΡΡΠΊΠΎΠ² Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠΎΠΌ 7β8 ΠΌΠΌ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΠΎΠΏΡΡΠ½ΠΎ-ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΠΎΠ³ΠΎ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π°. ΠΠΎΠ»ΡΡΠ΅Π½ΠΎ ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠ΅ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π΅Π½ΠΈΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ΅ΡΠ°Π»Π»ΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΌ Π°Π½Π°Π»ΠΈΠ·ΠΎΠΌ. ΠΠΎΠΊΠ°Π·Π°Π½Π° ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΡΠΎΡΠ΅ΡΠ°Π½ΠΈΡ ΡΠ°Π΄ΠΈΠ°Π»ΡΠ½ΠΎ-ΡΠ΄Π²ΠΈΠ³ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΠΊΠ°ΡΠΊΠΈ ΠΈ ΡΠΎΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΊΠΎΠ²ΠΊΠΈ Π΄Π»Ρ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΠΈΠ½Π΄ΡΡΡΡΠΈΠ°Π»ΡΠ½ΡΡ
ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΉ ΠΈΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½ΠΈΡ ΠΏΡΡΡΠΊΠΎΠ² ΠΌΠ°Π»ΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠ° Ρ Π²ΡΡΠΎΠΊΠΎΠΉ ΠΎΠ΄Π½ΠΎΡΠΎΠ΄Π½ΠΎΡΡΡΡ ΠΌΠ΅Π»ΠΊΠΎΠ΄ΠΈΡΠΏΠ΅ΡΡΠ½ΠΎΠΉ ΡΡΡΡΠΊΡΡΡΡ
Calculation of shape recovery in textured SM material
The aim of this work is to create a computer model predicting the strain to be accumulated and then recovered by nitinol superelastic textured sheets upon reversible martensitic transformation. Using an experimental orientation distribution function (ODF), connecting the microscale (grain) and macroscale (semiproduct) levels, the model calculations are realized through the following steps: (1) tensile loading is consecutively applied to the shape memory nitinol sheet in all directions from those rolling to transverse; (2) an external stress is transferred to micro (each grain) level, where the crystallographic strain is obtained by minimizing the total strain energy; (3) then the strains accumulated in each grain are translated backwards to the macrolevel through the ODF: to obtain the macrostrain accumulated by the whole sheet, a weighted summation of grain-accumulated strains is used by assuming the input from each grain orientation to be proportional to the corresponding ODF coefficient. This approach is validated for isotropic (constant ODF) and for normally anisotropic (typical experimental ODF) cases. It is also shown how the sharpening of texture gradually increases the strain anisotropy until the single crystal strain distribution of the unique grain orientation appears in the sheet plane
- β¦