Advanced Engineering Materials
Ni-based superalloys are widely deployed as structural materials in extreme operating environments of high temperature (700-1000°C) oxidizing conditions. Typical applications for these include the high-pressure stages of gas-turbines in aerospace and engine exhaust systems in high performance vehicles. While superalloy development in the 20th century has raised the operational limits of these materials impressively, systematic methods for designing new alloys rather than empirical means are yet to be fully exploited. The role of the different alloying elements and their optimum levels is further complicated at interfaces where oxidation effects can dramatically alter both alloy microstructures and chemistries. APT is one of the few techniques which can explore the atomic-scale chemistry of these highly complicated alloys.
Another area of research is the use of lightweight, high-strength Al alloys for improved fuel efficiency in automotive applications. Al-Mg-Si-(Cu) alloys, also known as 6XXX series alloys, are age hardened alloys which can contain a range of nanoscale solute clusters and precipitates, for which APT is well suited to observe. Combined chemical and morphological data can be used to explore these features and lead to the development of alloys with improved mechanical properties.