Comparison Between Micro Machining of Additively Manufactured and Conventionally Formed Samples of Ti6Al4V Alloy

The paper deals with micro mechanical machining process of Ti6Al4V alloy. A comparison between additively manufactured samples and conventionally fabricated samples with mill annealed structure was performed. Powder Bed Fusion Laser Based (PBF-LB) and Beam Based (PBF-BB) processes were used to produce samples with a building direction of 0° and 30° in relation to the plate. The Minimum Uncut Chip Thickness (MUCT) was determined to investigate the removal behavior during slot machining with rounded-edges micro-tools. The cutting forces were measured, and the loads were utilized to calculate Specific Cutting Force (SCF). It was reported as a function of the feed per tooth (fz) to investigate when the transition between shearing and ploughing occurs. Once the MUCT was identified, further micro machining tests were performed by changing the feed rate and speed rate. The surface roughness and cutting force of the machined samples were measured to deeply investigate the effects of ploughing regime. The dependence of roughness on the sample fabrication technique and on the process parameters of micro milling was highlighted.