Can we balance the high-efficiency and high sustainability in grinding of aero-engine hot-end component?

The aerospace industry faces critical challenges in manufacturing high-performance hot-end components—such as superalloy turbine blades and disks—which endure extreme temperatures (up to 2 000 °C) and mechanical stresses, demanding grinding to achieve high surface integrity and geometric tolerances. However, the low thermal conductivity of these materials leads to intense heat generation during grinding, causing workpiece burns, excessive energy consumption (5–10 times higher than conventional cutting), and reliance on unsustainable high-pressure coolant systems responsible for over 60% of grinding energy use and over 50% of carbon emissions.

Recently, a team of scientists led by Jiuhua Xu from Nanjing University of Aeronautics and Astronautics, China proposed a novel idea of high-efficiency-sustainable grinding of aero-engine hot-end component. This proposal can lead to significant reductions in energy use, carbon emissions, and coolant reliance, while maintaining or improving surface integrity and geometric accuracy.

The team published their work in Chinese Journal of Aeronautics on April 12, 2025.

“We propose an integrated solution combining ultrasonic vibration-assisted grinding (UVAG), heat pipe grinding wheels (HPGW), and minimum quantity lubrication (MQL) to realize high-efficiency precision machining with environmental sustainability.” said Wenfeng Ding, professor at College of Mechanical and Electrical Engineering at Nanjing University of Aeronautics and Astronautics (China), a senior expert whose research interests focus on the field of sustainable and hybrid-energy fields machining of aerospace difficult-to-cut materials.

“UVAG introduces high-frequency vibrations to disrupt inefficient rubbing and ploughing periods in traditional grinding, enhancing the chip formation stage by 10–50% and redirecting energy toward material removal rather than heat generation. This reduces grinding forces, minimizes thermal damage, and improves surface quality—critical for machining next-generation superalloys with hardness >500 HV and tensile strength >1500 MPa. Complementing this, HPGW embeds phase-change heat pipes within the wheel matrix to actively transfer over 65% of grinding heat during dry machining, eliminating dependence on external high-pressure coolants. This internal enhanced cooling system reduces energy consumption by 42% and carbon emissions by 56% compared to conventional methods while preventing surface burns. MQL further optimizes the process by delivering micron-scale lubricant droplets (10–100 mL/h) to form a friction-reducing film at the grinding interface, decreasing lubricant use by >90%, energy consumption by 45%, and waste treatment costs by 70–80% compared to flood cooling, while enhancing chip flashing.” said Wenfeng Ding.

These innovations establish a "thermo-mechanical synergistic regulation" framework: UVAG reduces heat generation at the source, HPGW ensures rapid heat dissipation, and MQL sustains lubrication efficiency with minimal environmental impact. “This triad overcomes the historical trade-off between high efficiency and sustainability, particularly for advanced superalloys that exceed the capabilities of traditional cubic boron nitride (CBN) wheels, which can lead to significant reductions in energy use, carbon emissions, and coolant reliance, while maintaining or improving surface integrity and geometric accuracy.” said Wenfeng Ding.

However, deep research on the heat-generation and energy transition mechanisms during the proposed high-efficiency-sustainable grinding process is still needed. And the temperature-control strategy and process-optimization for grinding of hot-end components also need further researching. 

Other contributors include Ning Qian, Jiuhua Xu from the College of Mechanical and Electrical Engineering at Nanjing University of Aeronautics and Astronautics, China.

Original Source

Ning QIAN, Wenfeng DING, Jiuhua XU. Challenges and solutions for high-efficiency-sustainable grinding of aero-engine hot-end components [J]. Chinese Journal of Aeronautics, 2025, https://doi.org/10.1016/j.cja.2025.103536.

About Chinese Journal of Aeronautics 

Chinese Journal of Aeronautics (CJA) is an open access, peer-reviewed international journal covering all aspects of aerospace engineering, monthly published by Elsevier. The Journal reports the scientific and technological achievements and frontiers in aeronautic engineering and astronautic engineering, in both theory and practice. CJA is indexed in SCI (IF = 5.3, top 4/52, Q1), EI, IAA, AJ, CSA, Scopus.