Effect of high-temperature thermomechanical treatment on the fine structure and mechanical properties of titanium alloys

1966 ◽  
Vol 8 (9) ◽  
pp. 730-732
Author(s):  
Ya. D. Vishnyakov ◽  
A. N. Ivanov ◽  
L. M. Mirskii ◽  
Z. Sh. Kherodinashvili
Keyword(s):  
Mechanical Properties ◽  
Fine Structure ◽  
High Temperature ◽  
Titanium Alloys ◽  
Thermomechanical Treatment

Effect of high temperature thermomechanical treatment on the fine structure of titanium alloys

1965 ◽  
Vol 7 (5) ◽  
pp. 312-316
Author(s):  
M. L. Bernshtein ◽  
L. A. Elagina ◽  
L. P. Fatkullina ◽  
N. M. Semenova
Keyword(s):  
Fine Structure ◽  
High Temperature ◽  
Titanium Alloys ◽  
Thermomechanical Treatment

scholarly journals HIGH TEMPERATURE OXIDATION OF TI-6AL-4V ALLOY FABRICATED BY ADDITIVE MANUFACTURING. INFLUENCE ON MECHANICAL PROPERTIES

2020 ◽  
Vol 321 ◽  
pp. 03006
Author(s):  
Antoine CASADEBAIGT ◽  
Daniel MONCEAU ◽  
Jonathan HUGUES
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Additive Manufacturing ◽  
Titanium Alloys ◽  
Oxidation Kinetics ◽  
High Temperature Oxidation ◽  
Effect Of Temperature ◽  
Premature Failure ◽  
Temperature Oxidation

Titanium alloys, such as Ti-6Al-4V alloy, fabricated by additive manufacturing processes is a winning combination in the aeronautic field. Indeed, the high specific mechanical properties of titanium alloys with the optimized design of parts allowed by additive manufacturing should allow aircraft weight reduction. But, the long term use of Ti-6Al-4V alloy is limited to 315 °C due to high oxidation kinetics above this temperature [1]. The formation of an oxygen diffusion zone in the metal and an oxide layer above it may reduce the durability of titanium parts leading to premature failure [2, 3]. In this study, Ti-6Al-4V alloy was fabricated by Electron Beam Melting (EBM). As built microstructure evolutions after Hot Isostatic Pressure (HIP) treatment at 920 °C and 1000 bar for 2h were investigated. As built microstructure of Ti-6Al-4V fabricated by EBM was composed of Ti-α laths in a Ti-β matrix. High temperature oxidation of Ti-6Al-4V alloy at 600 °C of as-built and HIP-ed microstructures was studied. This temperature was chosen to increase oxidation kinetics and to study the influence of oxidation on tensile mechanical properties. In parallel, two other oxidation temperatures, i.e. 500 °C and 550°C allowed to access to the effect of temperature on long-term oxidation.

scholarly journals Effect of Multistage High Temperature Thermomechanical Treatment on the Microstructure and Mechanical Properties of Austenitic Reactor Steel

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 63
Author(s):  
Sergey Akkuzin ◽  
Igor Litovchenko ◽  
Nadezhda Polekhina ◽  
Kseniya Almaeva ◽  
Anna Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
High Temperature ◽  
Thermomechanical Treatment ◽  
Cold Deformation ◽  
Solution Treatment ◽  
The State ◽  
Austenitic Steels ◽  
Dynamic Strain ◽  
Average Grain Size

The deformation microstructures formed by novel multistage high-temperature thermomechanical treatment (HTMT) and their effect on the mechanical properties of austenitic reactor steel are investigated. It is shown that HTMT with plastic deformation at the temperature decreasing in each stage (1100, 900, and 600 °C with a total strain degree of e = 2) is an effective method for refining the grain structure and increasing the strength of the reactor steel. The structural features of grains, grain boundaries and defective substructure of the steel are studied in two sections (in planes perpendicular to the transverse direction and perpendicular to the normal direction) by Scanning Electron Microscopy with Electron Back-Scatter Diffraction (SEM EBSD) and Transmission Electron Microscopy (TEM). After the multistage HTMT, a fragmented structure is formed with grains elongated along the rolling direction and flattened in the rolling plane. The average grain size decreases from 19.3 µm (for the state after solution treatment) to 1.8 µm. A high density of low-angle boundaries (up to ≈ 80%) is found inside deformed grains. An additional cold deformation (e = 0.3) after the multistage HTMT promotes mechanical twinning within fragmented grains and subgrains. The resulting structural states provide high strength properties of steel: the yield strength increases up to 910 MPa (at 20 °C) and up to 580 MPa (at 650 °C), which is 4.6 and 6.1 times higher than that in the state after solution treatment (ST), respectively. The formation of deformed substructure and the influence of dynamic strain aging at an elevated tensile temperature on the mechanical properties of the steel are discussed. Based on the results obtained, the multistage HTMT used in this study can be applied for increasing the strength of austenitic steels.

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