**Yezika Sánchez Hernández, Francisco Javier Trujillo Vilches \*, Carolina Bermudo Gamboa and Lorenzo Sevilla Hurtado**

Department of Manufacturing Engineering, EII, Universidad de Málaga, E-29071 Málaga, Spain; yezika.sanchez@uma.es (Y.S.H.); bgamboa@uma.es (C.B.G.); lsevilla@uma.es (L.S.H.)

**\*** Correspondence: trujillov@uma.es; Tel.: +34-951-952-245

Received: 27 June 2018; Accepted: 18 July 2018; Published: 23 July 2018

**Abstract:** The Ti6Al4V alloy is included in the group of difficult-to-cut materials. Segmented chips are generated for a wide range of cutting parameters. This kind of chip geometry leads to the periodic variation of machining forces, tool vibrations, and work part-tolerance inaccuracies. Therefore, the analysis of chip morphology and geometry becomes a fundamental machinability criterion. However, few studies propose experimental parametric relationships that allow predicting chip-geometry evolution as a function of cutting parameters. In this work, an experimental analysis of the influence of cutting speed and feed rate on various chip-geometric parameters in dry machining of the Ti6Al4V alloy was carried out. In addition, the chip morphology and chip microstructure were studied. A clear dependence of certain chip-geometric parameters on the cutting parameters studied was found. From the experimental data, several parametric relationships were developed. These relationships were able to predict the evolution of different geometric parameters as a function of cutting speed and feed, within the tested range of values. The differences between the proposed models and the experimental data were also highlighted. These parametric equations allowed quantifying the value of parameters in which the trend was clear.

**Keywords:** Ti6Al4V alloy; chip geometry; dry machining; parametric models
