scholarly journals Study on Microstructure Evolution and Mechanical Properties of Ti2AlNb-Based Alloy under Canning Compression and Annealing

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 980 ◽  
Author(s):  
Wang ◽  
Xu ◽  
Sun ◽  
Zong ◽  
Chen ◽  
...  

The influence of height reduction on the microstructure evolution and mechanical properties of the Ti2AlNb-based alloy was investigated during canning compression and subsequent annealing. After the annealing treatment, the spheroidized B2 phase grains occurred because of partial recrystallization. Meanwhile, the texture evolution of the B2 phase and O phase were analyzed under the deformation degree, ranging from 25% to 75%. The results show that the mechanical properties of the post-annealed alloys were co-affected by the grain size and Schmid factor of the B2 phase. When the height reduction was less than 25%, the compression strength was mainly affected by the grain size. When the height reduction was higher than 50%, it was mainly dominated by the Schmid factor. When the deformation degree reached 75%, the recrystallized grain size decreased to 0.9 μm. Meanwhile, the Schmid factor of a {110}<001> slip system in B2 phase reduced to 0.34. Therefore, the yield strength of the Ti2AlNb alloy at room temperature increased from 892 MPa in the as-rolled condition to 935 MPa after the canning compression and annealing.

2010 ◽  
Vol 667-669 ◽  
pp. 253-258
Author(s):  
Wei Ping Hu ◽  
Si Yuan Zhang ◽  
Xiao Yu He ◽  
Zhen Yang Liu ◽  
Rolf Berghammer ◽  
...  

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.


2018 ◽  
Vol 138 ◽  
pp. 165-173 ◽  
Author(s):  
Weicai Wan ◽  
Hongsheng Chen ◽  
Haibo Wang ◽  
Chongsheng Long ◽  
Qingzhu Sun ◽  
...  

2019 ◽  
Vol 116 (2) ◽  
pp. 219 ◽  
Author(s):  
Junjun Cui ◽  
Liqing Chen ◽  
Yanfei Li ◽  
Jiahua Liu ◽  
Jiaqi Xie

In order to improve mechanical properties of roll cast 8011 aluminum alloy (AA 8011) by grain strengthening, and expand its application field, the effect of different annealing treating processes on mechanical properties and microstructures of cryogenic rolled AA 8011 was investigated. The roll cast AA 8011 was cryogenic rolled for six passes and then annealed. The annealing treatment was adopted at 100–300 °C for 1 h, and then the annealing treatment was adopted at 220 °C for 10–80 min. The microstructures of AA 8011 under roll cast and cryogenic rolled states were studied by using OM. The grain size was calculated by the Image-pro-plus 5.0. The microstructures of AA 8011 under annealing states were observed by using TEM and energy dispersive spectrum analysis. The results show that the second phase Al8Fe2Si appears in the cryogenic rolled AA 8011 after annealing treatment. When the dislocation moves in the grain, the dislocation plays a pinning role, which is conducive to grain refinement. The optical annealing treatment was treated at 220 °C for 40 min with optimal thermal stability. The ideal grain size is 1 μm, hardness is 65 HV, and tensile strength is 202 MPa. It is about 1.5 times of the roll cast AA 8011.


2019 ◽  
Vol 944 ◽  
pp. 531-536
Author(s):  
Ke Jia Kang ◽  
Peng Fan ◽  
Jian Zhang ◽  
Qiang Guo Luo ◽  
Qiang Shen ◽  
...  

In this study, the W-Si-C multi-phase composites were fabricated by an arc melting method. With addition of SiC, the grain size of W is obviously reduced, and the small angle misorientation becomes dominate, which is beneficial for the improvement of deformability. The effects of SiC additions (from 0.5 to 3wt%) on the microstructure and mechanical properties are mainly investigated. With 1 wt% SiC addition, the flexural strength reaches the highest value. The self-generation of W5Si3 may enhance the strength and ductility, but too much W5Si3 exists as brittle BP (Brittle to Plastic) microstructure. The highest flexural strength is obtained at approximately 1 vol% W5Si3.


2005 ◽  
Vol 475-479 ◽  
pp. 549-554 ◽  
Author(s):  
H.S. Kim ◽  
Hyo Tae Jeong ◽  
Ha Guk Jeong ◽  
Woo Jin Kim

The softening of fine-grained ECAPed AZ31 Mg alloys could be ascribed to the texture modification during ECAP. Lower ECAP temperature is more effective in refining the microstructure. The strength of the ECAPed AZ 31 Mg alloys increased with decrease in grain size when they have similar texture.


2015 ◽  
Vol 661 ◽  
pp. 91-97
Author(s):  
Cho-Pei Jiang ◽  
Zong Han Huang

The aim of this research is to investigate the effect of grain size on the mechanical properties and deformability of titanium alloy in equal channel and cross-sectional reduction channel angular pressing process. Specimens made of grade 2 titanium alloy with diameter 5 mm are annealed to temperature of 500 °C to 1000 °C resulting in different initial grain sizes, thus underwent tensile test for obtaining mechanical properties. Molds for both processes are designed to carry out serve plastic deformation. Finite element models are created and simulated the deformation behavior according to the mechanical properties of tensile test. Experimental results show that small α-phase grain starts to form in 700 °C homogenization treatment and its grain size increases as an increasing of annealing temperature. The β-phase microstructure precipitates resulting in brittle behavior in 850 °C annealing treatment. Simulation result show that squeeze load of ECAP is larger than 100 ton but it can be reduced when exit angle of channel is larger than entrance. Outer corner of ECAP with 90 ̊ generate lower squeeze pressure than that of 40 ̊.


2020 ◽  
Vol 842 ◽  
pp. 155874
Author(s):  
Yuanhang Chen ◽  
Chunli Yang ◽  
Chenglei Fan ◽  
Yimin Zhuo ◽  
Sanbao Lin ◽  
...  

2011 ◽  
Vol 399-401 ◽  
pp. 419-424
Author(s):  
Yun Peng Zhu ◽  
Pei Peng Jin ◽  
Pei Tang Zhao ◽  
Wei Dong Fei ◽  
Jin Hui Wang ◽  
...  

The microstructure evolution and mechanical properties of Mg2B2O5 whiskers reinforced AZ31B magnesium composite during extruded were investigated using optical microscope and scanning electron microscope. Mg2B2O5w/AZ31B was fabricated by stir-casting and the as-cast ingot was machined into cylindrical billets. Then the hot extrusion was carried out at 350°C at a constant speed of 10 mm/s with extrusion ratio of 6.25:1. The mechanical properties (strength, ductility and hardness) were tested by tensile tests and hardness tests at room temperature. Typical microstructures of different positions of extruded stock showed the microstructure evolution law during extrusion processing. It was found that DRX took place and whiskers accelerated DRX during hot extrusion. The whisker distribution in the composites was improved by hot extrusion. Additionally, the vickers microhardness of the composites increased first, and then decreased with deformation degree increased.


Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 136 ◽  
Author(s):  
Dong ◽  
Zhang ◽  
Che ◽  
Yu ◽  
Meng ◽  
...  

The current work systematically investigated the microstructure, texture evolution, and mechanical properties of MDFed Mg-13Gd-4Y-2Zn-0.5Zr (wt%) alloy (GWZ) on the condition of high and low temperature cycle deformation. The high and low temperature cycle deformation was proposed on the basis of the conventional multi-directional forging (MDF) at decreasing temperature and annealing treatment. As a new method, it was aimed to timely uniform the microstructure and strengthen magnesium (Mg) matrix during the deformation process. A low accumulative strain of 3 after 1 pass resulted in a bimodal microstructure with undynamic recrystallized (unDRXed) regions and dynamic recrystallized (DRXed) grains, while a high accumulative strain of 12 after 4 passes lead to a homogeneous microstructure with fine DRXed grains. According to the experimental results, it indicated that the average grain size of 63 μm after homogenization treatment at 520 was refined remarkably to 5.20 μm after 4 passes at 420 °C through high and low temperature cycle deformation. The area fraction of DRXed grains was increased to 98.4%, which can be regarded as achieving complete DRX after 4 passes. The grain refinement was mainly caused by particle stimulation nucleation (PSN) and mechanism. As the MDF passes and accumulative strain increased, the basal texture was weakened and transformed from a strong basal texture to a random distribution gradually. Compared with conventional MDF at decreasing temperature, the mechanical properties were enhanced effectively. After 4 passes, the ultimate tensile strength (UTS), tensile yield strength (TYS), and failure elongation (FE) were 405 MPa, 305 MPa, and 13.1%, respectively.


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