Study on nano-treating of Al-Mg-Si-Cu alloys with TiC nanoparticles

The 6xxx series wrought aluminum alloys (Al-Mg-Si-Cu) provide good formability and high strength potential, especially with high Cu additions. However, the large freezing ranges of these alloys often cause hot cracking susceptibility in solidification-based processes, such as casting, welding, and 3D printing. In this work, nano-treating, which is to tune the manufacturability and microstructure of metals by a small addition of nanoparticles, was applied to Al-Mg-Si-Cu alloys during casting. This study shows that nano-treating can effectively refine microstructure, eliminate hot cracking, and promote the dissolution of alloying elements. Tensile tests showed that nanoparticles enable strengthening. An extensive study on the TiC nanoparticle effect on Al-Mg-Si-Cu with various Mg and Si contents was conducted. This work provides valuable insights for rational design of nano-treated Al-Mg-Si-Cu alloys to achieve optimal combination of strength and ductility.