Optimizing Mechanical Properties and Thermal Stability of Age Hardenable Aluminum Alloys through Theoretical Modeling, Alloy Modification and Thermal Mechanical Properties

摘要

This research was concerned with a practical approach to the design of an improved age-hardenable aluminum alloy for moderate temperature application. The process involved extensive empirical research, theoretical simulation and modeling, calculated phase diagrams and first principle calculations and analytical techniques. Microstructure characterization and analytical transmission electron microscopy were employed to refine the development of the quaternary Al-Cu-Mg-Ag phase diagram Differential scanning calorimetry and electron diffraction were implemented to investigate the microstructural evolution of the ternary alloys and to validate calculated equilibrium phase boundaries. Energy dispersive spectroscopy was also used to illustrate the effect of trace additions on the phase boundaries that are important for the thermal stability of this class of alloys. Computer simulation & modeling were used to identify the microstructure that will result in the optimal combination of mechanical properties. Unavailable parameters were calculated from first principle atomistic modeling. The major objective of this research program has been to illustrate the use of modeling and simulation in alloy design and therefore aid in the early insertion of new high performance materials.