Machinability of nanofluid prepared by CNTs@Lubricant compounds

This study introduces a nanofluid prepared by carbon nanotubes (CNTs) compounds in which liquid lubricants are encapsulated in, simultaneously enhancing thermal conductivity and enabling lubrication upon compounds triggered release. Four types of lubricants were encapsulated into CNTs to prepare the compounds, and the influences of concentration (wt.%), acidification time (h), speed (m/min) and feeding rate on turning performance were investigated. The results demonstrated that lubricants were successfully encapsulated into CNTs, achieving a filling rate of 20 ~ 35%. Nanofluids prepared using these compounds showed significant improvements in dispersibility, thermal conductivity, and surface wettability. Compared with conventional cutting fluids, compounds-based nanofluid reduced cutting force by 15%, cutting temperature by ~25%, surface roughness by 16%, and extended the tools life by 22% under minimum quantity lubrication (MQL) conditions. Surface analysis found that CNTs compounds enabled the controlled release of lubricants to form a self-lubricating tribo-film, thereby improving turning performance.