The relationship between microstructures and mechanical properties in friction stir lap welding of titanium alloy

被引:14
作者
Zhang, Z. [1 ]
Tan, Z. J. [3 ]
Wang, Y. F. [1 ]
Ren, D. X. [2 ]
Li, J. Y. [1 ]
机构
[1] Dalian Univ Technol, Dept Engn Mech, State Key Lab Struct Anal Ind Equipment, Dalian 116024, Peoples R China
[2] Dalian Univ Technol, Sch Automot Engn, Dalian 116024, Peoples R China
[3] China Aerosp Sci & Ind Corp, Beijing Aerosp Technol Inst, Beijing 100074, Peoples R China
关键词
Friction stir welding; Titanium alloy; Dislocation density; Microstructure; Mechanical property; ALUMINUM-ALLOY; PLASTICITY MODEL; STRAIN RATES; EVOLUTION; BEHAVIOR; FLOW; PERFORMANCE; SIMULATION; STRENGTH; STRESS;
D O I
10.1016/j.matchemphys.2022.127251
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The microstructures and the mechanical properties of friction stir lap welded Ti-6Al-4V were investigated by both experimental and numerical methods. Dislocation density evolution model was proposed to link the microstructural changes observed by scanning electronic microscope and simulated by Monte Carlo method with the mechanical properties measured by tensile tests and simulated based on dislocation evolutions. It was found that lamellar grains can be formed in the prior-beta grains in friction stir lap welding of Ti-6Al-4V. The dislocation density can be increased to 1.29 x 1014/m2-1.48 x 1014/m2 in friction stir welding, which is 1.29-1.48 times higher than the parent metal. The yield strength can reach 986.33 MPa-1055.77 MPa in as-welded state, which is 91.58%-95.66% of the parent metal. The predicted yield strength can agree well with experimental data. Higher temperature can reduce the dislocation multiplication and coarsen the microstructures in friction stir welding. Softening in stress-strain curves can be obviously found in the temperature range of 600-900 circle C.
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页数:10
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