Changes in the structural and textural state of titanium alloy VT41 after hot upsetting and annealing

2021 ◽  
pp. 40-50
Author(s):  
P. N. Medvedev ◽  
S. A. Naprienko ◽  
O. S. Kashapov ◽  
E. V. Filonova
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Gas Turbine ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Alloy Structure ◽  
Turbine Engine ◽  
Α Phase ◽  
Deformed State ◽  
Kinetics Of

A study of the structure of titanium alloy VT41 (Ti–Al–Si–Zr–Sn– β-stabilizers) was carried out on a sample subjected to hot upsetting in the (α+β)-region – conditions simulating the stamping of a disk of a gas turbine engine (GTE). The features of the formation of the textural state of primary and secondary globular grains, as well as the kinetics of their dissolution with an increase in the annealing temperature, have been determined. As a result of heat treatment at 995°C, the homogeneity of the alloy structure significantly increases comparing to the deformed state, which is associated with the recrystallization of lamellar and small-globular grains and the retention of primary globular grains of the α-phase. The sequence of structural changes has been established during the annealing within the temperature range from 950 to 1040°C.

Effect of Heat Treatment on the Damage Tolerance Properties of Ti-6Al-2Zr-2V-1.5Mo ELI Alloy Plate

2011 ◽  
Vol 690 ◽  
pp. 282-285
Author(s):  
Xiao Xiang Wang ◽  
Song Xiao Hui
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Fatigue Crack ◽  
Annealing Temperature ◽  
Damage Tolerance ◽  
Phase Zone ◽  
Alloy Plate ◽  
Β Phase ◽  
Α Phase ◽  
Treatment Conditions

Effect of heat treatment on the damage tolerance properties of a newly developed middle strength high damage tolerance Ti-6Al-2Zr-2V-1.5Mo ELI alloy plate has been investigated in this paper by testing fracture toughness and fatigue crack-extending rate of the plate under three heat treatment conditions and fractograph inspection of the samples. It has been found that with the increasing of the primary annealing temperature from 900°C to 950°C, the fracture toughness increased and the fatigue crack extending rate decreased significantly. Microstructural observation has found that the crack expanded through the α beaming and mainly are perpendicular to the α orientation in the lamellar structure which annealed in α+β phase zone. For the Widmanstaten structure, which can be obtained from annealing in single β phase zone, the continuous grain boundary α phase and α beaming boundary hinder the crack expanding significantly.

Ti-6Al-2Sn-4Zr-2Mo

Alloy Digest ◽  
1967 ◽  
Vol 16 (8) ◽  
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
High Temperature ◽  
Gas Turbine ◽  
Creep Strength ◽  
Heat Treating ◽  
Turbine Engine ◽  
Bearing Strength ◽  
Temperature Performance ◽  
Alpha Titanium

Abstract Ti-6Al-2Sn-4Zr-2Mo is a super-alpha titanium alloy providing an excellent combination of creep strength, tensile strength, toughness and stability to 1050 F. It is recommended for airframe and gas turbine engine requirements. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ti-52. Producer or source: Titanium Metals Corporation of America.

Kinetics of Growth of Gas-Saturated (Embrittled) Layers on Titanium during Vacuum Annealing

2021 ◽  
Vol 316 ◽  
pp. 821-826
Author(s):  
Alexey B. Bulkov ◽  
Vladimir V. Peshkov ◽  
Vladimir F. Selivanov
Keyword(s):  
Experimental Data ◽  
Titanium Alloy ◽  
Growth Kinetics ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Surface Cracks ◽  
Brittle Crack ◽  
Parabolic Relationship ◽  
Kinetics Of ◽  
Annealing Mode

The influence of the parameters of the vacuum annealing mode on the thickness of the embrittled layers, formed on the surface of titanium as a result of its interaction with the residual gases of the vacuumed space, is studied. The thickness and structure of the layers were determined on samples made of VT6 alloy obtained from sheet metal with a thickness of 3 mm. Annealing of samples in the temperature range of 500-750 °C was performed with air dilution from 10 to 3∙10-2 PA. The dimensions of the embrittled layers were determined by measuring the zone of brittle crack propagation in the fracture of the samples, and measuring the distance between the surface cracks in the embrittled layers, formed during bending deformation. To quantify the effect of vacuum annealing modes of sheet titanium alloy VT6 on the depth of the embrittled part of the formed oxide layer, it is proposed to use a parabolic relationship, characterized by the degree of growth and the constant of the embrittled layer. By processing experimental data, the effect of annealing time, temperature, and air dilution on the growth kinetics of the embrittled layers was established. Based on the obtained kinetic regularities of the growth of the embrittled layers, nomograms are constructed, to determine the size of the embrittled layer formed at the heating stage at different speeds up to the specified annealing temperature.

Crystallization Kinetics of Fe-DOPED A1203

1994 ◽  
Vol 357 ◽  
Author(s):  
Todd W. Simpson ◽  
Ian V. Mitchell ◽  
Ning Yu ◽  
Michael Nastasi ◽  
Paul C. Mcintyre
Keyword(s):  
Crystallization Kinetics ◽  
Annealing Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Time Resolved ◽  
Α Phase ◽  
Kinetics Of ◽  
Beam Deposition

AbstractTime resolved optical reflectivity (TRR) and Rutherford backscattering spectrometry (RBS) and ion channelling methods have been applied to determine the crystallization kinetics of Fe-doped A1203 in the temperature range of 900-1050°C. Amorphous A1203 films, approximately 250 nm thick and with Fe cation concentrations of 0, 1.85, 2.2 and 4.5%, were formed by e-beam deposition on single crystal, [0001] oriented, A1203 substrates. Annealing was performed under an oxygen ambient in a conventional tube furnace, and the optical changes which accompany crystallization were monitored, in situ, by TRR with a 633nm wavelength laser.Crystallization is observed to proceed via solid phase epitaxy. An intermediate, epitaxial phase of -γ-Al203 is formed before the samples reach the ultimate annealing temperature. The 5% Fe-doped film transforms from γ to α-A1203 at a rate approximately 10 times that of the pure A1203 film and the 1.85% and 2.2% Fe-doped films transform at rates between these two extremes. The Fe-dopants occupy substitional lattice sites in the epilayer. Each of the four sets of specimens displays an activation energy in the range 5.0±0.2eV for the γ,α phase transition.

scholarly journals Features of nickel alloy structure, conditions for crystallization and isolation of main and redundant phases during modification

2020 ◽  
pp. 35-39
Author(s):  
Yu. O. Filippov ◽  
◽  
E. N. Eremin ◽  
D. A. Sedykh ◽  
O. V. Kropotin ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Solid Solution ◽  
Growth Rate ◽  
Solidus Temperature ◽  
Structure And Properties ◽  
Alloy Structure ◽  
Additional Heat ◽  
Kinetics Of ◽  
Strengthening Phases

The influence of modification of heat-resistant nickel-based alloys on the crystallization kinetics of alloys was established by the methods of thermal analysis. This effect is expressed in the increase in solidus temperature and, as a consequence, narrowing the crystallization range of the alloy, the increase in the growth rate of a solid solution, and change in the temperature of precipitation of eutectic and strengthening phases. As a result, the use of modification with refractory particles makes it possible to exert an additional effect on the structure and properties of nickel-based alloys without additional heat treatment

scholarly journals Formation of Structure and Properties of Two-Phase Ti-6Al-4V Alloy during Cold Metal Transfer Additive Deposition with Interpass Forging

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4415
Author(s):  
Yuri Shchitsyn ◽  
Maksim Kartashev ◽  
Ekaterina Krivonosova ◽  
Tatyana Olshanskaya ◽  
Dmitriy Trushnikov
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Physical And Mechanical Properties ◽  
Metal Transfer ◽  
Layer By Layer ◽  
Structure And Properties ◽  
Two Phase ◽  
Cold Metal Transfer ◽  
Α Phase ◽  
Cold Metal

The paper deals with the main formation patterns of structure and properties of a titanium alloy of the Ti-6Al-4V system during additive manufacturing using cold metal transfer (CMT) wire deposition. The work aims to find the optimal conditions for layer-by-layer deposition, which provides the high physical and mechanical properties of the titanium alloy of the Ti-6Al-4V system hybrid, additively manufactured using CMT deposition. Particular attention is paid to interpass forging during the layered printing of the product. Additionally, we investigate how the heat treatment affects the structure and properties of the Ti-6Al-4V alloy that has been CMT-deposited, both with and without forging. These studies have shown that the hybrid multilayer arc deposition technology, with interpass strain hardening, allows the use of high temperature and high technology titanium alloys to obtain products of a required geometric shape. It has been proven that the interpass deformation effect during CMT deposition contributes to a significant decrease in the sizes of the primary β-grains. In addition, forging enhances the effect of microstructure refinement, which is associated with phase recrystallization in deformed areas. It is shown that the heat treatment leads not only to a change in the morphology of the phases but also to additional phase formations in the structure of the Ti-6Al-4V-deposited metal while the mechanism is realized and consists of the gradual decomposition of the martensitic α′-phase and the formation of a dispersive α2-phase. This structure formation process is accompanied by the dispersion hardening of the α-phase. The strength characteristics of the Ti-6Al-4V alloy obtained using layer-by-layer CMT with forging are given; they exceed the strength level of materials obtained with the traditional technologies of pressure treatment, and there is no decrease in plasticity characteristics. The use of the subsequent heat treatment makes it possible to increase the ductility characteristics of the deposited and forged Ti-6Al-4V material by 1.5–2 times without strength loss.

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