Micromilling of Lamellar Ti6Al4V: Cutting Force Analysis

The aim of this paper is to study the influence of a Ti6Al4V microstructure on cutting forces during the micromilling process. Samples were annealed above the β-transus at three different temperatures: 1020, 1050, 1080°C and then cooled in a furnace, air and water, in order to produce different Widmastätten microstructures. Micromilling tests were carried out on heat-treated samples and the cutting forces were measured by means of a load cell. The results were correlated to the sample microstructures, which were thoroughly investigated by means of an optical microscope, X-ray diffraction and microhardness measurements. The highest cutting forces were observed for soft and ductile furnace cooled samples, suggesting that the most important factor affecting workability is the material ductility, while hardness is a less relevant parameter.