Microstructure and Tensile Properties of Hot Worked High Nb Containing TiAl Alloy on Industrial Scale

2005 ◽  
pp. 785-788
Author(s):  
Jun Pin Lin ◽  
Xiang Jun Xu ◽  
Jian Feng Gao ◽  
Yan Li Wang ◽  
Zhi Lin ◽  
...  
2005 ◽  
Vol 475-479 ◽  
pp. 785-788
Author(s):  
Jun Pin Lin ◽  
Xiang Jun Xu ◽  
Jian Feng Gao ◽  
Yan Li Wang ◽  
Zhi Lin ◽  
...  

. A hot working and its effect on the microstructure and tensile properties of Ti-45Al-9 (Nb, W, B, Y) alloy ingot on industrial scale were investigated. The results showed that the alloy has good workability in anα+γphase region. An ingot on industrial scale was successfully extruded followed by multi-step canned forging. The initial microstructure of the alloy is fine full lamellar (FL) microstructure. After hot working a sound pancake exhibiting a fine grain duplex (DP) microstructure with grain size about 20μm was obtained. The as-forged alloy has more balanced tensile properties than the small heats with similar composition and microstructure at both room and high temperatures.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2757 ◽  
Author(s):  
Ning Cui ◽  
Qianqian Wu ◽  
Zhiyuan Yan ◽  
Haitao Zhou ◽  
Xiaopeng Wang

In this paper, the microstructure, deformability, tensile properties, and phase hardness of the Ti–43Al–2Cr–0.7Mo–0.1Y alloy with a high β phase content were investigated. Microstructural analysis showed that the β phase precipitated not only at the colony boundaries but also inside the lamellae due to its high content. A high-quality forging stock was prepared through one-step noncanned forging. The total deformation reached above 80%, suggesting that the alloy has good hot deformability compared to other TiAl alloys. The deformed microstructure was composed of fine and equiaxed grains due to dynamic recrystallization. The high β phase content was shown to contribute to the decomposition of the initial coarse lamellae. Tensile testing showed that the alloy has good room-temperature ductility, even if the β phase content reaches above 20%. This is inconsistent with a previous study that showed that a large amount of the hard β phase is detrimental to the room-temperature ductility of TiAl alloys. Nanoindentation testing showed that the hardness of the β phase in the current alloy is about 6.3 GPa, which is much lower than that in the Nb-containing TiAl alloys. Low hardness benefits the compatible deformation among various phases, which could be the main reason for the alloy’s good room-temperature ductility. Additionally, the influence of various β stabilizers on the hardness of the β phase was also studied. The β phase containing Nb had the highest hardness, whereas the β phase containing Cr had the lowest hardness.


2006 ◽  
Vol 14 (10-11) ◽  
pp. 1143-1150 ◽  
Author(s):  
M. Thomas ◽  
O. Berteaux ◽  
F. Popoff ◽  
M.-P. Bacos ◽  
A. Morel ◽  
...  

2012 ◽  
Vol 482-484 ◽  
pp. 1713-1717
Author(s):  
Bin Tang ◽  
Chuan Jing Chen ◽  
Zhi Yong Xue ◽  
Chun Jing Wu ◽  
Shuang Shou Li

The changes of the tensile properties of the full lamellar TiAl alloy under pre-compression were studied by means of pre-compression damage tests and tensile tests. The study indicated that:The changes of the tensile property of the damaged alloy at room temperature were different from that of high temperature. The mechanical property of the TiAl alloy degrades because of the present of the cracks, which decrease the load area of the alloy.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1381 ◽  
Author(s):  
Ning Cui ◽  
Qianqian Wu ◽  
Kexiao Bi ◽  
Jin Wang ◽  
Tiewei Xu ◽  
...  

This study systematically investigated the influence of multi-directional forging (MDF) on the microstructural evolution, hot deformation behavior, and tensile properties of a β-solidifying TiAl alloy. The initial lamellar microstructure of an as-cast alloy was remarkably refined and homogenized by three-step MDF. High temperatures and multi-pass deformations were conducive to the decomposition of lamellae. A crack-free billet was obtained through three-step MDF, with a deformation temperature of 1250 °C and a forging speed of 0.1 mm/s, indicating that MDF can be applied to β-solidifying TiAl alloys by the proper control of the alloy composition and process parameters. Microstructural observation showed that the billet mainly consists of fine and equiaxed γ grains and a small amount of β phase. The tensile properties of the multi-directional forged alloy were also significantly improved, due to microstructure refinement. The ultimate tensile strength (UTS) and elongation (δ) at room temperature were 689.4 MPa, and 0.83%, respectively. The alloy exhibits excellent ductility at 700 °C. When the temperature was increased to 700 °C, the UTS decreased to 556 MPa and δ increased to 5.98%, indicating that the alloy exhibits excellent ductility at 700 °C. As the temperature further increased to 750 °C, δ dramatically increased to 46.65%, indicating that the ductile-brittle transition temperature of the alloy is between 700 °C and 750 °C.


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