Investigation of nanoparticle concentration on lubrication performance in nanofluid minimum quantity lubrication assisted grinding of SiCf/SiC composites

SiC f /SiC ceramic matrix composites are essential for advanced aero-engines due to their thermal stability, low density, and oxidation resistance. The machining of SiC f /SiC composites with minimal damage remains a key challenge. Nanofluid minimum quantity lubrication (NMQL) can significantly enhance heat transfer and lubrication during grinding. This study thoroughly investigated the effects of dry grinding (DG), flood grinding, minimum quantity lubrication, and different volume fractions of carbon nanotubes (CNTs) nanofluids on the grindability of the material along with their economic implications. The results indicated that, in comparison to DG, the average feed forces were reduced by 55 % and 50.2 %, and the grinding temperature achieved its minimum under 2 %-CNTs lubrication conditions at grinding depths of 0.4 mm and 0.6 mm. Furthermore, the 2 %-CNTs approach achieved the lowest surface roughness and fiber wear, emerging as the most cost-effective solution. The 2 %-CNTs nanofluid demonstrated a small contact angle and elevated viscosity, preventing particle agglomeration or settling, while showing strong lubrication stability and wear resistance. This research provides theoretical guidance for low-damage processing of SiC f /SiC composites.