LIFT (Lightweight Innovations for Tomorrow) has launched a technology project focused on predicting the performance of aluminum-lithium alloys — important materials for the next generation of jet engines and other aerospace applications. Lead partners on the project, United Technologies Research Center, the University of Michigan, and Lockheed Martin, will work on advanced computer simulations to better understand and predict the performance of aluminum-lithium alloys in formed parts. This includes a predictive simulation tool that can be calibrated and validated against practical experience and various lab experiments to be performed at Case Western Research University and The Ohio State University.
“With the right computational tools we can design new components both faster and better,” said Alan Taub, chief technology officer at LIFT. “The newer designs can deliver the same performance using less material – saving even more weight using an already lightweight metal.”
Engineers are interested in lithium because it is the lightest metal found in nature – just one atomic number heavier than helium. When combined with aluminum, lithium creates an alloy that is both lighter and stronger than aluminum alone.
“Earlier aluminum-lithium alloys sometimes had issues with cracking or performing in high temperature environments,” said John Allison, LIFT technical leader for Integrated Computational Materials Engineering (ICME). “The latest generation of these alloys show great improvements in several areas, but we really need more integrated computer models to predict their performance at a number of steps, from their atomic structure right up to a finished component.”
Allison added, “Aluminum-lithium alloys often have a microstructure analogous to the grain in wood. It behaves differently when you bend it in one direction rather than another. The unique interdisciplinary team expects to develop what’s called crystal plasticity modeling to predict the final microstructure in an alloy. That in turn defines the mechanical properties of the alloy as it’s formed into a part.”
Alex Staroselsky, principal research engineer, United Technologies Research Center, is leading the industry side of the project partnership, which also includes material process modeling and simulation of the properties evolution during industrial operations. He said, “Any company interested in these alloys may benefit from what we develop, but we are really focused on improving turbine engine components for the aerospace industry.”