A new heat treatment invented by scientists in Germany could give old jet engine blades a second life, reduce the need for expensive replacements, and conserve critical raw materials.
Introduced by scientists at Ruhr University Bochum in Germany, the method uses high-pressure gas and heat to fix microscopic damage inside jet turbine blades. It could reportedly store the blades to their original state after 5,000 flight missions.
According to the team, the novel technology could make the blades suitable for reuse even years after mechanical stress, and exposure at extreme temperatures above 1,832 degrees Fahrenheit (1,000 degrees Celsius).
The initiative is part of a three-year project known as Second_Life, which began in August 2026. It also brings together the German Aerospace Center (DLR), aircraft engine repair specialist Lufthansa Technik, heat and surface treatment company Aalberts Surface Technologies, and metal-processing firm Otto Fuchs.
Restoring turbine blades
Jet engine blades are made to handle extreme temperatures that can sometimes exceed 2,732 degrees Fahrenheit (1,500 degrees Celsius), even above the melting point of the materials themselves. They also withstand rotational speeds of up to 16,000 RPM and enormous centrifugal forces.
They are produced from single-crystal nickel-based superalloys. Their atoms form a continuous crystal structure without grain boundaries, which could weaken the material at high temperatures. However, even these materials degrade.
Over time, the extreme conditions alter the blades’ internal structure and weaken them by creating tiny pores within it. First-stage turbine blades are often replaced after about 5,000 flight missions, equivalent to about three to six years of service.
“During turbine operation, the blades are subjected to tensile stress caused by rotational centrifugal forces at high temperatures and are damaged by what is known as creep fatigue,” Sebastian Weber, PhD, a researcher at the university, and study co-author, said.
To address the challenge, the scientists turned to a method known as hot isostatic pressing (HIP). The process involves heating damaged components under uniform gas pressure before rapidly cooling them.
It could potentially close the microscopic pores and restore the material’s original structure without destroying its single-crystal properties. “The restoration of the microstructure and mechanical properties is to be achieved through hot isostatic pressing, or HIP for short,” Louis Becker, PhD, another scientist at the university who helped lead the study, added.
Aviation sustainability
To test the technique, the team will first recreate real-world turbine blade damage at the German Aerospace Center. They will expose samples to high temperatures and mechanical stress to induce controlled creep-fatigue damage.
The samples will then undergo hot isostatic pressing at Ruhr University Bochum, where the researchers will determine the best treatment conditions and examine changes in the material’s microstructure. Subsequent mechanical tests will assess whether the treatment can restore the blades’ original performance.
The team’s ultimate goal is to prove that the damaged turbine blades can safely return to service after treatment and recoating. The technology has the potential to reduce the demand for newly produced turbine blades.
“By extending the service life of turbine blades, we can reduce both the demand for newly manufactured components and the associated consumption of energy and raw materials,” Weber concluded in a press release.