The Influence of Grain Size in Grade 4 Titanium on Surface Topography and Near–Surface Zone Microstructure Depending on Cutting Parameters

Due to their high stored internal energy, nanostructured materials can be susceptible to undesirable changes during turning/cutting machining, which is known to be a heat dissipation process and can negatively affect their unique properties. In this paper, ultrafine–grained Grade 4 titanium rods produced by equal–channel angular pressing–Conform are investigated. The results of experimental studies of the effect of the ultrafine–grained structure (grain size ~0.15 μm) formed in the rods on the roughness and microstructure of the near–surface deformed zone are presented as a function of the cutting parameters (cutting speed V, m/min; cutting depth t, mm; cutting feed S, mm / rev) in comparison with samples with coarse (~10 μm) grain. Differences in surface topography and chip morphology depending on the grain size of the machined titanium are discussed. The fundamental possibility of predicting the surface roughness of titanium alloys depending on grain size using artificial intelligence methods is demonstrated.