Rapid infrared heating is used to forge aluminum products. Credit: Queen City Forging
During forging, metal is heated to high temperatures until it becomes malleable and can be shaped by applying pressure. Oak Ridge National Laboratory and Cincinnati-based Queen City Forging developed a new method to forge aluminum using a hybrid rapid infrared furnace.
Why it matters:
Using rapid infrared heating for forging saves manufacturers time and energy compared to gas-powered combustion furnaces, and results in higher quality metal parts.
Real-world impact:
QCF has created 9 million aluminum impellers since adopting the technology in 2009. Impellors are part of turbocharger devices that pull in and compress air for more efficient engine combustion. Because they rotate at high speeds, impellers need to be durable. Using lighter-weight aluminum rather than titanium impellers improves engine performance and saves energy costs.
QCF now operates three conveyor rapid infrared furnaces at the same time, allowing the company to run multiple units and forging presses, making production four times faster.
The infrared furnaces have cut time and production costs. Powered by electricity, they have reduced energy use by 75%, saving 45 billion BTUs.
The benefits of rapid infrared heating:
- Better: Superior aluminum metallurgy compared to traditional convection oven heating, with improved microstructure, macrostructure, tensile strength, and fatigue properties.
- Faster: Faster, more efficient, and more consistent heating compared to traditional convection ovens. Infrared heating also enables quick reheating of metal for multiple-stage forgings. For one type of aluminum alloy, QCF reduced the heating time from four hours to just sixteen minutes.
- Cheaper: Using far less energy than traditional convection ovens, infrared furnaces also are less prone to breaking down, and are easier and quicker to repair, leading to less downtime.
The innovation:
A traditional convection oven heats air within a space. Warming this volume of air takes time, and the temperature can vary as air molecules circulate. Air molecules do not store heat for long, so the ovens must be run continuously.
Infrared heaters, in contrast, radiate wavelengths that are directly absorbed and stored by objects. Infrared light is a part of the electromagnetic spectrum that our eyes cannot see but we feel as heat — like when the Sun breaks through the clouds on a cold day and its warmth is felt immediately despite the cold air.
Infrared heating is not new, but it has not been used in aluminum manufacturing until now because the wavelengths often bounced off the reflective metal rather than be absorbed. ORNL researchers worked with QCF to test ways to abrade the surfaces of aluminum billets to reduce reflectivity. They determined blasting the metal with aluminum oxide and then tumbling the billets created a matte surface that allows aluminum to quickly absorb infrared wavelengths.
The rapid infrared furnace was built by Infrared Heating Technologies. ORNL researchers performed metallurgy tests on the abraded aluminum after rapid infrared heating and confirmed superior results.
Backed by science:
Supported by the U.S. Department of Energy’s Advanced Materials and Manufacturing Technologies Office within the Office of Energy Efficiency and Renewable Energy, this project highlights improvements in materials science and manufacturing while showcasing ORNL's commitment to innovation.
Deep dive:
- Read more about Queen City Forging.
- Watch a video about the Queen City Forging collaboration.
- Learn about the MDF Technical Collaboration program and how the MDF is accelerating manufacturing innovation.
The big picture:
By pairing rapid infrared heating with surface preparation techniques, U.S. manufacturers can produce stronger, lighter aluminum parts more quickly, potentially helping industries from automotive to aerospace cut costs and improve performance.
— Leslie Mullen
Read more stories about ORNL's science with impact.