Versatility of trace nano-TiC–TiB2 in collaborative control of solidification-rolling-welding microstructural evolution in Al–Mg–Si alloy for enhanced properties

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 851; p. 143661
• Main Authors: Liu, Tian-Shu, Qiu, Feng, Yang, Hong-Yu, Tan, Chao-Lin, Dong, Bai-Xin, Xie, Jian-Feng, Shu, Shi-Li, Jiang, Qi-Chuan, Zhang, Lai-Chang
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 23.08.2022; Elsevier BV
• Subjects: Aluminum alloys; Aluminum base alloys; Evolution; Guinier Preston zone; Heat affected zone; Magnesium; Mechanical property strengthening; Microstructure; Microstructure control; Nanoparticles; Recrystallization; Silicon; Solidification; Titanium carbide; Titanium diboride; Ultimate tensile strength; Welded joints; Welding; Yield strength; Nanoparticles; Aluminum alloys; Mechanical property strengthening; Microstructure control
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2022.143661

It is challenging to concurrently control the microstructure evolutions after undergoing casting, sheet forming and welding. This study successfully addressed this challenge via trace TiC–TiB2 nanoparticles in the amelioration of solidification-rolling-welding microstructural evolution. Nanoparticles refined the solidified microstructures and significantly increased the net driving force for recrystallization, promoting the precipitation of nanoscale Guinier–Preston zones and β'' phases. The coarsening of the fusion and heat-affected zones was also effectively suppressed. The yield strength (YS) and ultimate tensile strength (UTS) of the rolled plates were enhanced by 31.3% and 16.3%, respectively, without significantly sacrificing ductility. Additionally, the YS and UTS of the as-welded welding joints were enhanced by 30.2% and 7.8%, respectively. The amelioration mechanism of TiC–TiB2 throughout the microstructural evolution and strengthening process was systematically investigated. This study provides a typical model for the complete amelioration of microstructural evolution in aluminum alloys under multiple processing conditions. •The nucleation of solidified phases is promoted, and their growth is hindered.•Recrystallization and formation of coherent nanoscale precipitates are promoted.•Coarsening of fusion zone and heat affected zone is suppressed.•Building better microstructure configuration for improved properties.