Papers by Author: J. Salguero

Abstract: Manufacturing Engineering Processes Knowledge Area has developed an innovative teaching experience in order to give, only in one session, a complete view of a basic subject, Manufacturing Engineering. This experience has been developed on the basis of making a cube constructed in card by groups of students. Starting from this, the different steps of a manufacturing process have been identified, as well as the necessity of establishing a quality control for any of them. Moreover, the different material processing technology types have been distinguished, the concept of process performance has been introduced and the different possibilities for sequential and/or parallel processing have been analyzed. On the basis of this, the students have built the topics program of the subject, justifying its competences distribution. In the same way, the students have defined the related basic concepts. At the end of the course, a questionnaire containing the basic cognitive concepts was answered by them, 100% successfully.

Abstract: In this work, Stereoscopic Optical Microscopy (SOM), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) have been applied for analyzing the evolution of tool wear during the dry turning process of aerospace Al-Cu alloys. The results derived from this analysis have revealed that secondary adhesion is the main tool wear mechanism that takes place in such process. So, in the first instants of the machining process, a Built-Up Layer (BUL) is developed onto the tool rake face by thermomechanical causes, promoting the conditions for developing a Built-Up Edge (BUE) which grows to a critical size. Starting from it, BUE is extruded giving rise to secondary BUL-BUE effects. When these are removed, tool particles are dragged out provoking the tool wear.

Abstract: Titanium based alloys, mainly UNS R56400 (Ti6Al4V), are increasingly being applied in the airship building industry due to its excellent physicochemical properties. Machining operations are usually required in the manufacturing processes of Ti based aerospace structural elements. However, high reactivity of Ti provokes a quick tool wear. So, in order to reach an economically acceptable production level, it is necessary to minimize the costs associated to tool wear. In this work, Scanning Electron Microscopy (SEM), Stereoscopic Optical Microscopy (SOM) and Energy Dispersive Spectroscopy (EDS) have been used for both analysing and identifying secondary adhesion mechanisms that are taking place when an aeronautical titanium alloy is machined. Special severe cutting conditions have been applied. Thus, titanium alloy have been dry machined with TiN coated WC-Co tools. Results obtained have shown that tool wear is controlled by a secondary adhesion mechanism, which presents two stages. A first stage is constituted by a TiOx multi-film formed onto the tool surfaces. A second step involves the mechanical adhesion of the alloy material to those surfaces. When this material is removed, tool particles are dragged off causing tool wear.