Eck Industries exclusively licenses cerium-aluminum alloy co-developed by ORNL; high-temperature automotive and aerospace applications
8 June 2017
Eck Industries has signed an exclusive license for the commercialization of a cerium-aluminum (Ce-Al) alloy co-developed by the Department of Energy’s Oak Ridge National Laboratory that is ideal for creating lightweight, strong components for advanced vehicles and airplanes.
Aluminum alloys at present are limited to applications below 230 °C due to the rapid loss of mechanical characteristics at higher temperatures; however there is a need for aluminum alloys that have good castability and maintain mechanical characteristics above that temperature. Scientists at ORNL, working with Eck Industries and researchers at DOE’s Ames and Lawrence Livermore national laboratories, developed the Ce-Al alloy that is easy to work with, lightweight, corrosion-resistant, and exceptionally stable at high temperatures—making it ideal for automotive, aerospace, power generation, and other applications.
The patent-pending alloy was developed as part of DOE’s Critical Materials Institute (CMI) and makes use of cerium, the most abundant rare earth element. Cerium makes up as much as half of mined rare earths, yet has less value than co-mined elements such as neodymium and dysprosium that are in high demand for advanced energy technology applications. Creating new uses for cerium supports both domestic rare earth mining operations and the US manufacturing sector.
As outlined in the patent application, the cast alloy includes aluminum and from about from about 5 to about 30 wt% of at least one of cerium, lanthanum, and mischmetal. The cast alloy has a strengthening Al11X3 intermetallic phase in an amount in the range of from about 5 to about 30 wt%, wherein X is at least one of cerium, lanthanum, and mischmetal.
The Al11X3 intermetallic phase has a microstructure that includes at least one of lath features and rod morphological features. The morphological features have an average thickness of no more than 700 µm and an average spacing of no more than 10 µm, the microstructure further comprising an eutectic microconstituent that comprises more than about 10 vol% of the microstructure.
Testing has shown the Ce-Al alloy is stable at 500 ˚C. Withstanding higher temperatures means, for instance, that engines made using the alloy can run hotter with more complete fuel combustion while being lighter in weight, which advances fuel efficiency.
Ce-Al does not require additional thermal processing during the casting process and takes advantage of abundant, low-cost cerium, said ORNL scientist Orlando Rios. Casting with the alloy can be accomplished using standard aluminum foundry practices and without a protective atmosphere. Rios and colleagues described the castability, structure, and mechanical properties of binary, ternary, and quaternary Al-Ce based alloys in a 2016 paper in JOM, the journal of Minerals, Metals & Materials Society.
The alloy is thermodynamically stable, Rios said. The cost of heat treatment and the additional machining required due to thermal distortion can make up some 50-60% of the cost of casting traditional alloys. Energy costs could potentially be reduced by 30-60& compared with traditional casting processes, he noted. The Ce-Al alloy’s potential marks a significant departure from post-casting heat treatment and age-hardening approaches developed over some 100 years and can significantly advance manufacturing competitiveness as result, Rios added.
Eck, a privately-owned business based in Manitowoc, Wis., was involved in developing and testing of the alloy under a separate agreement. The company has been producing aluminum castings for customers in the military, automotive, aerospace, energy, medical, and industrial markets since 1948.
The involvement of multiple national laboratories and industry via CMI’s interest in leveraging scientific knowledge to help solve critical materials issues was essential to fast development of the alloy. ORNL researchers led the development team while focusing on casting and microstructure property stability. Ames ran experiments on thermo-mechanical processing and examined the thermo-physical properties of the Ce-Al alloy. Lawrence Livermore performed characterization work using advanced microscopy and other methods. Eck was involved in pilot-scale experiments and provided manufacturing insight and expertise.
CMI’s strategy is to bring together industrial, academic, and national lab expertise to address US reliance on critical materials like rare earth elements that are essential to energy, defense, and other manufacturing sectors.
It’s tough for a mine to survive if half of its output has no market. This alloy creates a use for the cerium that accompanies scarce and critical rare earths like neodymium and dysprosium.
—CMI Director Alex King
Castable High-Temperature Ce-Modified Al Alloys (US 20170096730 A1)
Zachary C. Sims, D. Weiss, S. K. McCall, M. A. McGuire, R. T. Ott, Tom Geer, Orlando Rios (2016) “Cerium-Based, Intermetallic-Strengthened Aluminum Casting Alloy: High-Volume Co-product Development” JOM Volume 68, Issue 7, pp 1940–1947 doi: 10.1007/s11837-016-1943-9