The influence of heat treatment on the formation of the structure and the level of mechanical properties of high-alloyed titanium alloy

Author(s):  
I. R. Kozlova ◽  
E. V. Chudakov ◽  
N. V. Tretyakova ◽  
Yu. M. Markova ◽  
E. A. Vasilieva

The paper investigates the possibility of increasing the strength of the experimental high-alloyed titanium alloy due to various methods of thermal action, leading to a change in its phase composition and intragrain structure. Changes in mechanical properties in correlation with the change in structure in the annealed, tempered and heat-hardened state are reviewed. It is shown that by controlling phase transformations in highalloyed two-phase titanium alloys, it is possible to realize high-strength state with satisfactory plastic characteristics. The optimal complex of mechanical properties is provided by heat treatment, which leads to the creation of a two-phase heterogeneous structure with a developed bimodal intragrain structure.

2021 ◽  
Vol 1016 ◽  
pp. 906-910
Author(s):  
Xin Hua Min ◽  
Cheng Jin

In this paper,effect of the different forging processes on the microstructure and mechanical properties of the flat flat billets of TA15 titanium alloy was investigated.The flat billiets of 80 mm×150 mm×L sizes of TA15 titanium alloy are produced by four different forging processes.Then the different microstrure and properties of the flat billiets were obtained by heat treatment of 800 °C~850 °C×1 h~4h.The results show that, adopting the first forging temperature at T1 °C、slow cooling and the second forging temperature at T2°C 、quick cooling, the primary αphases content is just 10%, and there are lots of thin aciculate phases on the base. This microstructure has both high strength at room temperature and high temperature, while the properties between the cross and lengthwise directions are just the same. So the hot processing of the first forging temperature at T1 °C、slow cooling and the second forging temperature at T2°C 、quick cooling is choosed as the ideal processing for production of aircraft frame parts.


2021 ◽  
Vol 1032 ◽  
pp. 152-156
Author(s):  
Peng Lei ◽  
Shu Cheng Dong ◽  
Guang Yu Ma ◽  
Tuo Cheng ◽  
O.M. Ivasishin

TC16 titanium alloy is a martensite α+β two-phase high strength titanium alloy, which can improve its structure and enhance properties through heat treatment. Effect of annealing process on microstructure and tensile properties of TC16 titanium alloy was investigated using optical microscope, scanning electron microscope and universe tensile test machine. The results show that when annealed at 720°C for 4h then furnace cooling to ambient temperature, the tensile strength of the TC16 alloy reaches nearly 900MPa,the elongation reaches 19.6% and the reduction of area reaches 65%, which present a good comprehensive performance.


Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 652
Author(s):  
Mykola Chausov ◽  
Oleg Khyzhun ◽  
Janette Brezinová ◽  
Pavlo Maruschak ◽  
Andrii Pylypenko ◽  
...  

Improvement in the mechanical properties of sheet two-phase high-strength titanium alloy VT23 due to impact-oscillatory loading and the use of carbon nanosolutions at room temperature was tested experimentally. It was shown that in addition to obtaining a significant increase in the initial plastic deformation of the alloy, it is possible to strengthen the surface layers of the alloy by a factor of 8.4% at a time via the impulse introduction of energy into the alloy and the use of carbon nanosolutions. Using X-ray photoelectron spectroscopy (XPS), it was first found that strengthening of the surface layers of the titanium alloy at a given load, in line with using a carbon nanosolution, leads to the formation of a mixture of titanium oxide and titanium carbide or oxycarbide of type TiO2−xCx on the surface.


2014 ◽  
Vol 59 (4) ◽  
pp. 1713-1716 ◽  
Author(s):  
R. Dąbrowski

Abstract Mechanical properties of the two-phase titanium alloy Ti6Al7Nb, after the heat treatment based on soaking this alloy in the α + β range, cooling in water or oil and ageing at two selected temperatures, were determined in the hereby paper. The alloy mechanical properties were determined in tensile and impact tests, supported by the fractographic analysis of fractures. In addition, its hardness was measured and the analysis of changes occurring in the microstructure was performed for all variants of the alloy heat treatment. Regardless of the applied cooling rate of the alloy, from a temperature of 970°C followed by ageing at 450 and 650°C, none essential changes were noticed in its microstructure. It was shown that applying less intensive cooling medium (oil) instead of water (before tempering) decreases strength properties indicators, i.e. tensile strength and yield strength as well as hardness (only slightly). The decrease of the above mentioned indicators is accompanied by an increase of an elongation and impacts strength. Fractures of tensile and impact tests are of a ductile character regardless of the applied heat treatment.


2018 ◽  
Vol 770 ◽  
pp. 31-38 ◽  
Author(s):  
Fei Yang ◽  
Brian Gabbitas ◽  
Stiliana Raynova ◽  
Ajit Pal Singh ◽  
Leandro Bolzoni

Ti-5553 (Ti-5Al-5V-5Mo-3Cr, wt. %) alloy is a recently developed near β titanium alloy and it has a very good hardenability, good ductility and high strength. In this study, we discussed the feasibility of preparing Ti-5553 alloy by different processes from powder mixtures of hydride-dehydride titanium powder, elemental powders and master alloy powders, including (1) direct extrusion of powder compact in argon, (2) extrusion of the vacuum-sintered billet in air and (3) extrusion of the hot-pressed billet in air. XRD, OM and SEM were used to determine the phase constitutions and microstructures of the prepared Ti-5553 alloys, and mechanical test was performed to examine their mechanical properties. The results showed the microstructures and phase constitutions of Ti-5553 alloys were significantly affected by different processes, which resulted in the relevant mechanical properties. The effect of the selected heat treatment on the microstructures and properties of Ti-5553 alloy were investigated as well.


2017 ◽  
Vol 265 ◽  
pp. 785-788
Author(s):  
A.V. Zhelnina ◽  
A.G. Illarionov ◽  
M.S. Kalienko

VST5553 titanium alloy is high strength (α + β) - transition alloy which is used for the production of heavy-duty parts [1]. It is known [2], that the cooling rate changing during the heat treatment can change the phases ratio in the alloy. With regards to the VST5553 alloy, this may be due to different cooling rates over the cross section of large-sized semi-finished goods. This in turn affects a complex of properties. Thus, it is necessary to know the effect of the cooling rate of two-phase region on the structure and properties, particularly the VST5553 alloy. However, the research in this area is not sufficient enough. The present study is devoted to this issue.


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