Tool wear suppression in diamond turning NAK80 via carbon nanofluids composite cryogenic nitrogen

Abstract

Diamond turning is an essential machining method for precision molds and dies. However, iron-carbon chemical affinity leads to severe graphitization of diamond tools when machining iron-based materials. Therefore, it is important to develop new techniques to suppress diamond graphitization. In the present study, an assisted machining method based on carbon nanofluid composite cryogenic nitrogen (CNFCCN) is proposed. Firstly, the influence of different concentrations of carbon nanofluid (CNF) and temperatures of cryogenic nitrogen (CN) on the machining performance was investigated. Secondly, by analyzing the negative effects of CNF-assisted machining at different concentrations and CN-assisted machining at different temperatures on the machined surface quality, CNFCCN-assisted machining at the appropriate concentrations and temperatures were selected, and the effects of CNFCCN-assisted machining on the machined surface quality were investigated. Thirdly, the suppression of graphitization wear of diamond tools by different assisted machining was evaluated by comparing the changes in tool material composition. Finally, the suppression effect of different assisted machining on diamond tool wear was assessed by analyzing the wear width of the flank face. The results show that the machined surface quality is improved by 25.7 % and a 50.9 % tool wear suppression effect is achieved under the machining of 0.25 % CNF composite −20 °C CN. This study provides valuable theoretical and experimental guidance for ultra-precision turning of iron-based materials.