José Manuel Arroyo Osorio

Simulation and verification of parametric numerical control programs using a virtual machine tool

A parametric computer numerical control (CNC) program was developed to make a test complex surface on a vertical milling machine equipped with an external fourth rotational axis. Parametric programming was used in order to get higher flexibility of the manufacturing process. The ball-end milling process was simulated and verified in a virtual model of the machine tool developed with the module integrated simulation and verification of the product lifecycle management software of Siemens NX7®. After that, the real process was carried out on the shop floor to machine the test surface. This demonstrates that the virtual machine tools are an effective resource to simulate and verify the performance of machining processes controlled by CNC parametric programs. The possibility of accurately simulating the parametric CNC program reduces the risk of its implementation and enables a more frequent use of this efficient feature of contemporary CNC machine tools.Abstract A parametric computer numerical control (CNC) program was developed to make a test complex surface on a vertical milling machine equipped with an external fourth rotational axis. Parametric programming was used in order to get higher flexibility of the manufacturing process. The ball-end milling process was simulated and verified in a virtual model of the machine tool developed with the module integrated simulation and verification of the product lifecycle management software of Siemens NX7®. After that, the real process was carried out on the shop floor to machine the test surface. This demonstrates that the virtual machine tools are an effective resource to simulate and verify the performance of machining processes controlled by CNC parametric programs. The possibility of accurately simulating the parametric CNC program reduces the risk of its implementation and enables a more frequent use of this efficient feature of contemporary CNC machine tools.

Resistencia a la corrosión de recubrimientos de NbC sobre acero AISI 316L depositados por UMB

In this work NbC coatings were deposited on AISI 316L steel substrates by reactive unbalanced magnetron sputtering. The coatings were deposited at room temperature to avoid heating alterations in the steel substrate microstructure, without bias and with a thickness of 200 nm. The coatings microstructure was characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Adherence of the coatings was evaluated using the scratch test and its corrosion resistance was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy in a 3.5% NaCl solution. The results indicate that the coating NbC has (111) preferential orientation, exhibits good adhesion and has good corrosion resistance for stainless steels protection.

Building a virtual machine tool in a standard PLM platform

Building a virtual machine tool model not only is advantageous for collision prevention and process planning in machining manufacturing operations, but also is a didactic resource for training users about operating physical machine tools. A generic procedure for developing a numerically controlled virtual machine tool in a standard PLM (product lifecycle management) platform is given. The procedure was applied to model the Hartford SMC5 machining center using the software Siemens NX 9. The first step in the process simplifies the machining center into a hierarchy of components using kinematic chains; the second step assigns information regarding motion to each machine component; the final step controls the movements of the machine components by means of a virtual controller and a postprocessor. Once complete, a validation procedure of the model is provided by modeling, simulating, and executing the manufacturing process of a selected workpiece with complex surfaces.