Author: Jie YuanPublisher:
ISBN:
Category :
Languages : en
Pages : 209
Book Description
Its high alloying makes it prone to solidification defects. Thus, plastic deformation is required to close shrinkage porosity, making this alloy for wrought products only. Moreover, this alloy has a limit of maximum Mg content at 1.8% as a high Mg content would form bulky Al2CuMg phase in the matrix, which has a limited solubility during solutionizing. Nanoparticles successfully reduced the solidification defects and greatly recovered the ductility of the cast alloy. In summary, this dissertation first discussed a new interface-controlled mechanism for in-situ synthesis of ceramic nanoparticles to build a solid foundation for economical nano-treating of molten metals. Then the nano-treating effects on solidification and heat treatment were systematically studied. Finally, two critical effects from nano-treating were summarized: "antibody effect" to enable scalable manufacturing of various high-strength aluminum alloys without cracking and shrinkage porosities and "vitamin effect" to improve microstructure and properties of alloys. The effects were successfully demonstrated to develop and manufacture high-performance aluminum alloys: manufacturing high-strength Al-Zn-Mg-Cu alloy, natural aging to AA7075 welds with nano-treated welding wires, and casting of high-strength Al-Cu-Mg alloys.