Performance of a cemented carbide self-lubricating tool embedded with MoS₂ solid lubricants in dry machining

Four micro-holes were made using a micro-EDM on the rake and flank face of cemented carbide (WC/TiC/Co) tools. Molybdenum disulfide (MoS₂) solid lubricants were embedded into the four micro-holes to form self-lubricating tools (SLT-1 and SLT-2). Dry machining tests on hardened steel were carried out with an SLT-1 self-lubricating tool with four micro-holes embedded with MoS ₂ solid lubricants in the rake face, an SLT-2 tool with four micro-holes embedded with MoS₂ in the flank face, an SLT-3 tool with four micro-holes embedded without MoS₂ in the rake face, an SLT-4 tool with four micro-holes embedded without MoS₂ in the flank face and a conventional tool SLT-5. The cutting forces, tool wear, and average friction coefficient at the tool-chip interface were measured and compared. Finite Element Analysis (FEA) was used to analyze the effect of micro-holes on the mechanical properties of cutting tools. It was shown that the cutting performance of SLT-1 and SLT-2 self-lubricated tools were greatly improved compared with that of SLT-3, SLT-4, and SLT-5 tools. The SLT-1 self-lubricating tool possessed the lowest friction coefficient, while the SLT-2 self-lubricating tool resulted in a lower flank wear. It is indicated that cemented carbides embedded with MoS₂ solid lubricants in the wear face is an effective way to reduce the rake and flank wear of conventional tools.