Relationship among solution heating rate, mechanical properties, microstructure and texture of Al-Mg-Si-Cu alloy
(1. Key Laboratory of Impact and Safety Engineering, Ministry of Education, Ningbo University, Ningbo 315211, China;
2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China)
2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China)
Abstract: The relationship among heating rate, mechanical properties, microstructure and texture of Al-Mg-Si-Cu alloy during solution treatment was investigated through tensile test, scanning electron microscope, X-ray diffractometer and EBSD technology. The experimental results reveal that there is a non-monotonic relationship among solution heating rate, mechanical properties, microstructure and texture. As the solution heating rate increases, the strength variations are dependent on the tensile direction; work hardening exponent n decreases first, and then increases; plastic strain ratio r increases first, and then decreases, and finally increases. The final microstructure and texture are also affected by heating rate. As heating rate increases, the microstructure transforms from elongated grain structure to equiaxed grain structure, and the average grain size decreases first, and then increases, and decreases finally. Although the texture components including CubeND{001}á310？ and P{011}á122？ orientations almost have no change with the increase of heating rate, the texture intensity and volume fraction decrease first, and then increase, and finally decrease. Both microstructure and texture evolutions are weakly affected by heating rate. Improving heating rate is not always favorable for the development of fine equiaxed grain structure, weak texture and high average r value, which may be related to the recrystallization behavior.
Key words: Al-Mg-Si-Cu alloy; solution heating rate; mechanical properties; microstructure; texture