Grain refinement mechanism and mechanical properties of TA15 alloy during multi-directional isothermal forging

被引：0
|
作者：
Ji X.-H. [1 ]
Li P. [1 ]
Shi Y.-B. [1 ]
Yan S.-L. [1 ]
Xue K.-M. [1 ]
机构：
[1] School of Materials Science and Engineering, Hefei University of Technology, Hefei
来源：
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | 2019年 / 29卷 / 11期
基金：
中国国家自然科学基金;
关键词：
Dislocation strengthening; Fine grain strengthening; Grain refinement mechanism; Mechanical properties; Multi-directional isothermal forging; TA15; alloy;
D O I：
10.19476/j.ysxb.1004.0609.2019.11.08
中图分类号：
学科分类号：
摘要：
The multi-directional isothermal forging (MDIF) experiments of TA15 alloy were carried out on at 600℃. The grain refinement mechanism, mechanical properties and fracture morphologies were analyzed by metallographic microscopy, electron backscattered diffraction, quasi-static tensile testing and scanning electron microscopy, respectively. The results show that, after 3 cycles of MDIF, the grains are refined significantly. The size of equiaxed α is reduced from 9.8 μm to 5.1 μm and the thickness of lamellar α is reduced from 4.6 μm to 2.3 μm. The grain refinement mechanism is the interaction of strain-induced continuous dynamic recrystallization by cross-slip and mechanical geometry breaking. The comprehensive mechanical properties are significantly improved. After 3 cycles of MDIF, the ultimate tensile strength increases to 1782 MPa, 54% higher than that of the initial state alloy, and the elongation rate only decreases by 5.8%. Through quantitative analysis, it is found that the combination of fine grain strengthening and dislocation strengthening results in an increase in ultimate tensile strength, and the contribution of fine grain strengthening is more significant. © 2019, Science Press. All right reserved.
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页码：2515 / 2523
页数：8
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