Internal-cooling grinding wheels for aerospace difficult-to-cut materials: design, fabrication, and performance

In aerospace manufacturing, the widespread application of difficult-to-machine materials such as titanium alloys, nickel-based superalloys, and composites imposes stringent requirements on grinding precision, efficiency, and surface integrity. A core bottleneck constraining high-performance machining is grinding-induced thermal damage, where high heat flux density leads to excessive temperature rise, causing workpiece surface burn and rapid wheel deterioration. Internal-cooling grinding wheels, featuring integrated coolant channels that deliver fluid directly to the grinding zone, offer a key technological solution by significantly enhancing heat dissipation efficiency and suppressing temperature spikes. This paper systematically reviews recent research advances in the design theory, fabrication techniques, and performance evaluation systems for internal-cooling grinding wheels. Regarding design theory, the focus is on coolant channel structure design, elucidating existing channel types and their underlying theoretical principles; the influence of grain distribution patterns and grain type selection on machining quality is also clarified. In the fabrication section, machining methods for the wheel body and various bonding techniques for attaching the abrasive layer to the base are summarized. For performance evaluation, a multi-dimensional assessment framework integrating grinding temperature field measurement and surface quality characterization (including roughness, topography, and microhardness) is presented to evaluate existing internal-cooling wheels. Finally, the review concludes with a summary and future outlook, providing foundational support for developing novel composite internal-cooling wheels with both high cooling efficiency and long service life, thereby offering theoretical insights and technological pathways for the precision grinding of aerospace difficult-to-machine materials.